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Posted by: Raymond McDougall on 06.13.2017 | Filed under: Latest, Mineral Shows | Comments (0)

 

I’m publishing this one a bit later than I expected this year, but I hope you will enjoy the content all the same. And for those of you who are in hot summer places, perhaps harking back to northern spring will feel refreshing…

Each year, I personally love the arrival of the Rochester Mineralogical Symposium for two reasons.

First, it’s my favourite annual event in Mineral World. And second, the RMS always marks the arrival of spring out here in the Bancroft woods, with nicer temperatures and the occasional chance to drive with the windows down again.

So, in this photo taken the day before the Symposium, I’ll leave it to you as to whether Emery’s happy expression was about hanging out the window and soaking up the early spring sunshine or the arrival of RMS 2017…

Emery Window

…but my own happiness that day was about both!

If you’ve attended the RMS, you’ll know why it’s special. The Rochester Symposium is a unique event. It brings together professionals and amateurs, and a complete range of subjects in specimen mineralogy. It is collegial and friendly, meant for collectors and those who love to learn about minerals. The RMS prominently features What’s New in Minerals each year. It is also a mineral show with excellent dealers set up and open when the talks are not on. And the RMS is a true mineral community with great cameraderie – it’s a time for hanging out and having a good time with mineral friends, new and old. It’s possible a drink or two is shared among us, and a few mineral songs are always sung.

If you haven’t yet come, I hope you’ll join us next year. Rochester is meant for you as much as anyone! You can reserve the dates right now: April 19-22, 2018.

2017 RMS Presentations

Opening – Bill Pinch

We began the 2017 (44th) RMS acknowledging the passing of our friend Bill Pinch, the great mineral collector who began the Symposium 44 years ago. As this had happened only three weeks before the Symposium, this was a hard period for Bill’s family and friends.

At RMS 2017, the Program Notes began with an In Memoriam, written by Chairman Steve Chamberlain – I have reproduced it in full, below. Bill’s website hosts both a great In Memoriam by Mark Feinglos (which he wrote for The Mineralogical Record) and some other great links – I include the link below, under Links and References.

Steve also announced that RMS 2018 will be dedicated to Bill’s memory and, in celebrating him, we will have a Bill Pinch theme. In addition to a presentation about Bill himself, there will be talks on the subjects he loved most during his collecting career, including Tsumeb, rare minerals, and collecting fine minerals.

Bill was a good friend and a kind mentor to me. What we enjoyed most – as I’m sure was true with so many of his mineral friends – was losing all sense of time together talking about minerals. And so that’s what we all did at RMS 2017 – we enjoyed each other’s company and immersed ourselves in minerals.

The King of Tides: Nova Scotia’s Bay of Fundy

I gave the first talk of the 44th Rochester Symposium, about the minerals of the Bay of Fundy. For those of you who know my website, you will have seen the articles I have posted on the blog (Collecting the Bay of Fundy, and Collecting on the Islands). Although the RMS presentation was about the minerals from the classic Bay of Fundy localities discussed in the blog posts, I had a different goal in putting it together.  My goal was to share not only the story and scenery, but specifically some of the top specimens, to show how great they can be. Those specimens reside primarily in a few Canadian collections, and so there was a collaborative effort to track them down and photograph them. This talk was only possible with the involvement of several people, so the presentation slides have four additional authors – Terry Collett, Ronnie Van Dommelen, Michael Bainbridge and David Joyce. Together, our efforts resulted in a well-received talk and many photographs of specimens that, until now, have not been well-known beyond our local circles. Some stunning pieces have been found on the Bay of Fundy.

Chabazite, Wasson's Bluff, Cumberland Co., Nova Scotia

Chabazite, Wasson’s Bluff, Cumberland Co., Nova Scotia – 7 cm
Terry Collett collection, Ronnie van Dommelen photo.

RonnieChabazite

Chabazite on Heulandite, Wasson’s Bluff, Cumberland Co., Nova Scotia – 14 cm
Ronnie Van Dommelen collection and photo.

DaveTwinChabazite, Wasson's Bluff, Cumberland Co., Nova Scotia

Chabazite, contact twin, Wasson’s Bluff, Cumberland Co., Nova Scotia – 1.2 cm crystal
(Penetration twins are common at Wasson’s Bluff, but contact twins are not.)
David Joyce collection and photo.

Copper, Cape D'Or, Nova Scotia, Beckett Collection, Michael Bainbridge photo

Copper, Cape D’Or, Cumberland Co., Nova Scotia – 15 cm
Largest spinel-law-twinned crystal 5 cm
Robert Beckett collection, Michael Bainbridge photo.

Copper, Cape D'Or, Cumberland Co., Nova Scotia
Copper, Cape D’Or, Cumberland Co., Nova Scotia – crystal 15.7 cm
Rod and Helen Tyson collection, Michael Bainbridge photo.

Thomsonite, Cape D'Or, Cumberland Co., Nova Scotia, George Thompson specimen, M. Bainbridge Photo

Thomsonite, Cape D’Or, Cumberland Co., Nova Scotia – 10.5 cm
Originally in the Doug Wilson collection, now George Thompson collection,
Michael Bainbridge photo.

18cm wide

Natrolite, Diamond Island, Five Islands, Cumberland Co., Nova Scotia – 18 cm
Ronnie Van Dommelen collection, Michael Bainbridge photo.

6.7cm high

Stilbite, Five Islands, Cumberland Co., Nova Scotia – 5.7 cm
Rod and Helen Tyson collection, Michael Bainbridge photo.

Michael Bainbridge is taking superb photos for collectors and publications these days – a link to his website is below, under Links and References.

Overview of Silicate Structures 

At the last minute, Dr. Frank Hawthorne was unable to attend and present at the RMS. Thanks to an above-and-beyond effort by Dr. Robert Lauf, this talk was in fact still presented at the RMS – Bob was up into the wee hours of the night working with the original slides to that he could then give both this talk and his own talk on Friday morning.

Bob gave a tough subject and it was a great morning for learning. After a late night of fun with friends, it’s not easy to greet the next morning in a dark presentation room hearing the opening statement “silicates are a complex business…”

However, this talk gave context and focus for what is in fact an important issue in mineral work.

Silicate structures have been generally understood since the 1930s, when William Bragg developed the silicate groups that are still in use today. Those groups are defined on the basis of the nature of the structural organization within the minerals. Silicates are all defined by having a silicon-oxygen tetrahedron- SiO4 – at the heart of their structure, and the key differentiating factor among silicates derives from the way in which each such Si04 tetrahedron is linked to others. This linkage is determined by the way in which the SiO4 tetrahedron shares the other elements within the mineral. This can result in chains, rings and other arrangements, and as a result, the silicates are grouped on this basis – inosilicates, cyclosilicates, orthosilicates, tetrasilicates.

Silicate structures are vitally important, and this talk highlighted why. When we are conducting analyses to identify and define minerals, we can know certain things from chemical analysis, but ultimately we may need to combine chemical and structural analysis to arrive at a proper definition and identification. In fact, structural analysis can be determinative. For example, the mineral wiluite is identified conclusively by understanding the structure – the structure will reveal which site in the mineral’s composition is occupied by boron, and that is determinative in the correct identification.

The silicates require much more structural work. Although definitive work has been completed with other mineral groups, the same cannot be said for the silicates – it is an overwhelmingly large subject, with lots yet to be done.

Orthosilicates

Fresh off giving the first talk, Bob Lauf was up at the podium to give the talk he had planned to give – an overview of the orthosilicate minerals. The orthosilicates include many awesome minerals, such as the titanite group, the zircon group, the garnet group, the humite group, vesuvianite and topaz, and this talk included many photos.

Clinohumite

Clinohumite, Jikhan, Koksha Valley, Badakhshan, Afghanistan 2.5 cm crystal
R. Lauf specimen and photo.

The orthosilicates are defined not by chains or rings, but by isolated groups of SiO4 tetrahedra. Bob likened the results of packing these SiO4 groups, together with the metals, to packing groups of organized ball bearings, with configurations that vary mineral to mineral. In general, the orthosilicates have dense, tightly-packed structures, and this can often mean a high surface hardness and toughness – many of these minerals survive weathering exceptionally well. Meanwhile, properties like cleavage, striations and crystal forms are determined by the metals within the structure, not the SiO4 tetrahedra.

Bob has a new book out, Collectors’ Guide to Orthosilicates. A link is below under Links and References.

 Grossular CaliforniaGrossular, Calixico, California – 8 cm
R. Lauf specimen and photo.

Technical Session

Every Friday afternoon at the RMS, we have what we colloquially call the “Technical Session”, Contributed Papers in Specimen Mineralogy, moderated by Dr. Carl A. Francis. This session is packed with great 15-minute talks on a range of topics, some completely specimen-oriented, some more mineralogical. I don’t write at length in these blog posts about the Technical Session talks, because the abstracts from these talks are published during the year in Rocks and Minerals magazine (don’t forget to watch for them!) and they are published in the RMS Program Notes.

However I really want to highlight the Technical Session for a moment this year. One reason is because the Technical Session is one of the features that makes Rochester unique, with professionals and amateurs all contributing. For collectors, there is a lot of interest in these talks – sometimes about rare or new minerals or finds, sometimes about localities, sometimes about scientific work done to establish fakes in Mineral World. And perhaps even more this year than in recent memory, we had a high percentage of truly excellent talks given by students. The group from the Department of Geology and Environmental Earth Science, Miami University, Oxford, Ohio did a particularly outstanding job. Too often, we look around Mineral World and see fewer young people than we’d all like – these students represent a bright future for mineralogy and the science that underpins everything we enjoy in Mineral World.

Friday Night

The Monteponi Mine, Sardinia, Italy

Our Friday night presentation was The Monteponi Mine, Sardinia, Italy, given by Dr. Renato Pagano, one of the world’s pre-eminent mineral collectors. The Renato and Adriana Pagano Collection includes 13,500 specimens, and 4,300 species, making it one of the most remarkable collections ever assembled.

Renato gave a great talk on this classic locality, with great photos. One of my favourite facts from the talk was the origin of the name Monteponi (since we’ve all seen it on musuem labels and in the literature for decades…).  The name has evolved from its original name, Monte Paone. Paone was an old Italian word meaning peacock, so it is Mount Peacock. Monteponi is a slightly (!) older locality than our New World ones – the Carthaginians mined silver-bearing galena there from the 6th century BC, and Monteponi later provided silver and lead to the Roman Empire, particularly for coinage and pipes, respectively.  Renato took us through the history and stories from the past, including the tragic incident in which one of the great phosgenites was presented as a gift to a clumsy Swedish ambassador who dropped and destroyed it.

Among collectors, Monteponi is most famous for having produced the world’s finest phosgenite crystals.

I had to include this one in this post  – I have loved this crystal for about 40 years, as its photograph was featured in one of the first mineral books I ever owned, as a child (Encyclopedia of Minerals and Gemstones).

Phosgenite, Monteponi, Sardinia, Roberto Appiani photo Phosgenite, Monteponi, Sardinia, Italy – 2.5 cm crystal
Milan Natural History Museum specimen, Roberto Appiani photo.

And here are two great phosgenite specimens from the Pagano collection:

Phosgenite Monteponi Pagano Collection Roberto Appiani photo

Phosgenite in a vug in galena, Monteponi, Sardinia, Italy – 6 cm
Renato and Adriana Pagano collection, Roberto Appiani photo.

Phosgenite Monteponi Pagano Collection Roberto Appiani photo

Phosgenite crystals, Monteponi, Sardinia, Italy – 2 cm
Renato and Adriana Pagano collection, Roberto Appiani photo.

Monteponi is also known as a locality for exceptionally fine anglesite crystals.

Anglesite Monteponi Pagano Collection Roberto Appiani photo

Anglesite, Monteponi, Sardinia, Italy – 8 cm
Renato and Adriana Pagano collection, Roberto Appiani photo.

A comprehensive article on Monteponi by Renato, together with Wendell Wilson, is included in The Mineralogical Record, November-December 2014, Vol. 45, No. 6 . If you haven’t yet read it, it’s superb, and if you read it when it came out, maybe time for another read…

Saturday – Annual What’s New

At the heart of the Rochester Symposium for decades, the annual Saturday morning presentations have captured highlights of what has been new in Mineral World over the prior year or so, focusing on fine mineral specimens for collectors.

What’s New in Minerals and Localities – Part I – Jeff Scovil

Jeff Scovil leads our worldwide survey of exceptional new mineral specimens, with an hour of stunning photos. It doesn’t matter who was up for how long having fun the night before, the room is always packed. Jeff’s presentation is always a Symposium highlight!

So here are a few photos to give you a sense – imagine an hour of this… It’s Mineral Heaven!

Euclase

Euclase, La Marina Mine, Muzo District, Boyaca, Colombia
Crystals to 5 cm
Irv Brown collection, J. Scovil photo.

Djurleite2

 Djurleite, Aït Ahmane MineBou Azzer, Ouarzazate, Morocco – 4 cm
Steve Smale collection, J. Scovil photo

Djurleite1
Djurleite, Aït Ahmane Mine, Bou Azzer, Ouarzazate, Morocco – 6 cm
Fine Gems and Minerals specimen, J. Scovil photo

Wulfenite China Jeff Scovil

Wulfenite, Jianshan Mine, Xinjiang, China – 4.3 cm
Sam Yung specimen, J. Scovil photo.

Apophyllite Bowtie Jeff Scovil

Fluorapophyllite, Aurangabad, Maharastra, India – 3.2 cm
Spirifer specimen, J. Scovil photo.

Elbaite Morocco

Elbaite tourmaline with albite, Ouarzazate, Morocco – 3.3 cm
Spirifer specimen, J. Scovil photo.

Fluorite Jeff Scovil photo

Fluorite, Huanggang Mines, Inner Mongolia, China – 8.9 cm
Steve Smale collection, J. Scovil photo.

And this last one may not be quite as recent, but the photo is, and the lighting on these crystals is simply as good as mineral photography can get…

Wulfenite Red Cloud Jeff Scovil

Wulfenite, Red Cloud Mine, Trigo Mountains, La Paz Co., Arizona – 3.9 cm
Unique Minerals specimen, J. Scovil photo.

Jeff is the Yoda of mineral photography. If you would like him to photograph your minerals, or you are looking for mineral photos for a publication, his website is under Links and References.

What’s New in Minerals and Localities – Part II

Part II of What’s New in Minerals is open to contributions from attendees. We had a couple of presentations about new books, including one mineral book, an upcoming book by Van King on Franklin, New Jersey, so we’ll keep our eyes open for that.

I then presented a few more examples of what has been new in Mineral World over the last year or so. If you’ve been following this website over the past year, you’ll be familiar with most of these.

Just a note of explanation about photographs here. Below each photo, I am including a link to the applicable blog post on the website where you can see more photos and specimens than are here. (Every new mineral update on this website is represented by a blog post, so even if you didn’t see a specimen before it sold and was removed, there is a nice record of my favourite photos from each update preserved in the blog.)

I’ll begin with the “Synchysite Mystery”… this goes back to a find from 2015, but the analytical work was completed in 2016…

In late 2015, I had posted on the website a small number of “synchysite” crystals from Novo Horizonte, Bahia Brazil. Although they had been sold to me as synchysite, some question arose as to confirmatory identification of these, in part thanks to some work that was ongoing to describe the new mineral parisite-(La) (described in my Tucson 2017 blog post). Analysis by Don Doell, first at the lab at University of Arizona, began to confirm more about their identity. Don then conducted semi-quantitative EDS at SGS Labs and narrowed things down. These are in fact phosphate mineralization: they are likely a combination of rhabdophane-(La), rhabdophane-(Ce) and possibly including monazite-(Ce). They appear to be pseudomorphs after a REE carbonate, probably in the parisite group, given that parisite-(La) has been found at Novo Horizonte in crystals with a similar aspect and appearance, at a similar time (therefore possibly similar part of the deposit). They could also be after bastnasite-(La), which has been described from the locality, although these are most similar in aspect to the parisite-(La) crystals. For now, I’m labelling them rhabdophane, pseudomorph after parisite, with the proviso that the above is the technically closest identification information to date. Thanks very much to Don for this analysis!

Rhabdophane, ps Parisite, Novo Horizonte, Bahia, BrazilRhabdophane, ps Parisite, Novo Horizonte, Bahia, Brazil – 4.3 cm
(More photos/specimens)

 A few other “What’s New” entries:

Aragonite, Mamsa, nr. Sidi Ayed, Boulemane Province, Fes-Meknes Region, Morocco

Aragonite, Mamsa, nr. Sidi Ayed, Boulemane Province, Fes-Meknes Region, Morocco – 6.9 cm
W.W. Pinch collection.
(More photos/specimens)

 Rutile, var. Struverite-Ilmenorutile, Santa Rosa Mine, Itambacuri, Doce Valley, Minas Gerais, Brazil

Rutile, var. Struverite-Ilmenorutile, Santa Rosa Mine, Itambacuri, Doce Valley, Minas Gerais, Brazil – 3.1 cm
(More photos/specimens)

 Wodginite, Linopolis District, Divino das Laranjeiras, Minas Gerais, Brazil

Wodginite, Linopolis District, Divino das Laranjeiras, Minas Gerais, Brazil – 3.2 cm
Jack Smith collection.
(NB: If you are interested in these, I was able to acquire five more in Ste. Marie and they will be on the website soon)
(More photos/specimens)

Red Phantom Quartz, Orange River, Cape Province, South Africa

Quartz with Red Phantoms, Orange River, Northern Cape Province, South Africa – 5.2 cm
(More photos/specimens)

More Saturday Presentations

mindat.org – Sixteen Years On: How mindat is Driving New Scientific Discoveries

Jolyon Ralph followed with a talk about mindat as it is today, status, and uses. (Jolyon has presented to the RMS on mindat before, so this was an update). As perhaps all of you know, mindat.org is a “Wikipedia”-like site for mineral information, contributed by users and monitored by administrators. What fewer of you may know (along with me, I didn’t!) is that mindat now hosts over 5 million pages, including 800,000 photographs and profile information for 280,000 localities. (!) (As an aside, Jolyon calculated that the information on mindat would now print a stack of paper 5 km tall.)

Jolyon explained how mindat is now being used for scientific studies and more analytical use. He highlighted that mindat is now being used to draw links between localities, particularly with a view to predictive occurrence among similar types of deposits and occurrences. He also explained that an important consideration when using mindat relates to the biases of users and contributors. For example, there is far more collector interest in crystals of wulfenite than there is in crystals of nepheline, so the amount and quality of information on mindat for wulfenite is different than it is for nepheline.

Mindat is an incredible resource and it was interesting to hear the new ways in which it is being used.

Upside Down and In the Future – Mining Tasmania’s Adelaide Mine

Saturday afternoon was amazing. John Cornish led off with his great talk about the Adelaide Mine in Tasmania, the world’s preeminent crocoite locality. John is involved with the Adelaide Mine project and shared his experience with enthusiasm! He took us on a tour of the mine region, with great information on local flora, fauna and history. And then he took us underground, to see pockets of crocoite up to 7×4 metres. (!) Just amazing…

Crocoite Pocket at the Adelaide Mine, Tasmania, John CornishCrocoite Pocket at the Adelaide Mine, Tasmania
John Cornish photo.

There was one particular story I had not heard and really enjoyed…

All field collectors must adapt to the conditions and nature of the occurrence they are working. What that means in practice is that often the tools that will be of most help will vary wildly from one mineral locality to the next. And I think it’s safe to say that all of us who have done field work for a long time have found resourceful ways of addressing issues, and collecting more efficiently. Often, the need for resourcefulness is driven by our desire to minimize the risk to specimens in the extracting process. Clearly, care is required when collecting crocoite! And in his focus on minimizing damage, John had a resourceful way of minimizing percussion and therefore lowering the risk of popping crocoite crystals off…

Crocoite Underground at the Adelaide Mine, Tasmania, John CornishTrimming crocoite matrix with a hand saw, underground at the Adelaide Mine, Tasmania
Brilliant!
John Cornish photo.

Some of the specimens recovered from the Adelaide Mine have been huge. Sometimes with large specimens in the field, we might include a prospector’s pick for scale. But in this case, John simply had himself included for scale.

Crocoite from the Adelaide Mine, Tasmania, John Cornish Crocoite from the Adelaide Mine, Tasmania
A very happy, if dirty, John Cornish for scale.

Crocoite from the Adelaide Mine, Tasmania, John Cornish

Crocoite from the Adelaide Mine, Tasmania
John Cornish photo.

John’s enthusiastic account was a highlight of RMS 2017.

If you are interested in seeing a bit more online about the Adelaide Mine, and more crocoite specimens, I am including a link to the Adelaide Mining Company’s website below, under Links and References.

Red Cloud Mine – The World’s Greatest Wulfenite Locality

John’s talk was a hard act to follow, but was Les Presmyk ever up to the task…

Les presented on the Red Cloud Mine, a locality that has inspired many of us as collectors since we began collecting minerals. Who doesn’t dream at night of perfect, glassy, sharp, lustrous. red-orange bevelled-square wulfenite crystals from this legendary mine? (Be honest.)

The Red Cloud is located in the Trigo Mountains, near the western border of southern Arizona. It was named after the prehistoric Red Cloud Trail, which leads to the west, on the California side of the Colorado River nearby.

Les took us through the early history of the mine, with some fascinating insights. One I liked was the explanation that because it is so relatively barren with no trees, lumber had to be brought in for quite a distance and was therefore expensive. Of course they did this to timber the mine tunnels, but it was too expensive for miners’ homes. So, the miners made their homes by digging tunnels into the side of the hill, to protect themselves and their belongings from the elements.

This presentation focused on significant mineral collecting at the Red Cloud over the years, beginning with Ed Over’s famous finds in the 1930s, and detailing the 1990s project by Wayne Thompson, James Horner and Les. During this time, the Red Cloud Mine was developed as an open pit operation, specifically for wulfenite specimens.

The most striking fact for me about this project was that from 1995 through 1999, only one significant pocket was found during the entire project – the 1997 pocket, that measured approximately 6 ft x 4 ft. That was it. For all the money spent on each year’s mining, very little was found. After major overburden removal beginning in 1995, and mining for months in advance of the Tucson show in early 1997, the team had assembled one flat of “decent” specimens from vugs and small pockets (under 10cm). Later in 1997 they hit the significant pocket, and from then until they stopped, very little was found – scare pockets and a few good specimens.  Suffice it to say, for the period following the 1997 pocket, the expenses far exceeded the value of specimens recovered. This puts into real perspective just how remarkable it is to have excellent Red Cloud wulfenite specimens from any era – they are rare and have come out of the ground at major cost.

Wulfenite Red Cloud Scovil

Wulfenite, Red Cloud Mine, Trigo Mountains, La Paz Co., Arizona – 10.7 cm
Les and Paula Presmyk specimen, J. Scovil photo.

Wulfeniteonquartz.RedCloudMine.Scovil2011-04-0081

Wulfenite, Red Cloud Mine, Trigo Mountains, La Paz Co., Arizona – 4.3 cm
Les and Paula Presmyk specimen, J. Scovil photo.

This was a super talk!

Just as an aside, Red Cloud has been written about a lot, given its legendary status among mineral localities.  Of the many published articles and chapters in books, I particularly like the accounts in “Collecting Arizona, State of Mines, Legacy of Minerals” (recounted by Tony L. Potucek, Les Presmyk, Richard Graeme and others, edited by Terry Wallace with Gloria Staebler, Ray Grant, Suzanne Liebetrau and Tom Wilson, published by Lithographie, 2012), and I personally was originally inspired by the Red Cloud Mine section in Peter Bancroft’s classic “Gem and Crystal Treasures” (published by Western Enterprises-Mineralogical Record, 1984). These are good reads – I highly recommend them.

Sunday Finale

By Sunday morning, it was time to recover from all the orange and red crystals from Saturday afternoon.

In past years, we have sometimes had lower attendance on Sunday mornings, but again this year Sunday morning was most-hands-on-deck. (Granted a few stragglers had had too much fun Saturday night.)

Meet an Important Unknown Mineralogist

Belgian collector Herwig Pelckmans led off with a talk that was fascinating, and not only for its subject matter. In his research and work on certain minerals, Herwig had come across the name Vaes, in connection with several uncommon species, and he was curious to know who “Vaes” was. However, when he looked him up, there was almost no information readily available. And so Herwig began an extensive research investigation that led him eventually back to the family and descedants, as he learned about the mineralogist Johannes Vaes (1902-1978). Vaes was a Dutch mining engineeer who became a mineralogist in the Democratic Republic of the Congo. He worked with the company Union Miniere du Haut Katanga, and he identified and defined several new minerals.

Johannes Vaes, CongoJ. F. Vaes in Jadotville (now called Likasi), when he was most likely in his early thirties.
Unknown photographer. Copyright H. Pelckmans

Vaes was at the famous Shinkolobwe Mine, and it was here that he made his discoveries.

Shinkolobwe
Old Belgian postcard showing the open pit of the Shinkolobwe uranium mine, printed by Nels.
Notice the original French spelling of the locality. Photo and copyright H. Pelckmans.

One striking fact about Vaes’ discoveries is that the only scientific instrument he had at his disposal was a polarizing microscope.

Saleeite, Shinkolobwe, Paul DeBondt

Saleeite, Shinkolobwe Mine, Shinkolobwe, Katanga Copper Crescent,
Katanga, Democratic Republic of the Congo
Field of view 3.6 cm
Paul De Bondt specimen and photo.

The mineral vaesite (NiS2) is named in his honour.

Vaesite, nepouite, uraninite, Shinkolobwe

Vaesite with Nepouite coating, associated with black uraninite crystals
Shinkolobwe Mine, Shinkolobwe, Katanga Copper Crescent,
Katanga, Democratic Republic of the Congo
Field of view 3.5 cm, vaesite crystal 1.1 cm.
Paul De Bondt specimen and photo.

At the end of this talk, we had an example of one of the great things about the RMS – the amazing pool of mineral knowledge and mineral history knowledge that is collected together in that ballroom. Van King was able to add an extra footnote to the talk, giving further context for the mineral collecting community: he was able to share that Vaes had in fact been the boss of famous mineral dealer Gilbert Gauthier (who was ultimately responsible for handling many of the fine DRC specimens that now grace collections around the world).

The Pioneer District, Pinal County, Arizona – The Silver King and Magma Mines

Les Presmyk gave the final talk at RMS 2017, about the Silver King Mine and the Magma Mine in the Pioneer District. This was another excellent presentation, with detailed historical accounts and wonderful historical photos. This one really struck me – today, it is hard to imagine horse/mule-drawn ore trains.

Silver King, Ore Wagon, 1880s.AHS

Mule-drawn ore wagons at the Silver King Mine, 1880s. AHS Photo.

This part of the talk is very well represented by Les’s recent excellent article in The Mineralogical Record, “The Arizona Silver Belt: Silver King to McMilllenville”, The Mineralogical Record July-August 2015, Vol. 46:4.

Les then spoke about the famous Magma Mine, where he had worked as a mining engineer. This mine is probably best known among collectors for the glassy barites it produced, but it also produced some wonderful calcite specimens.

Calcite.MagmaMine.3700L.Scovil2011-07-0105

 Calcite, 3700 Level, 4D Stope, Magma Mine, Superior, Pinal Co., Arizona -11.1 cm
Les and Paula Presmyk specimen, J. Scovil photo.

Barite.3600.4D.Magmamine.Superior.Scovil2011-07-0096

  Barite, 3600 Level, 4D Stope, Magma Mine, Superior, Pinal Co., Arizona – 7.1 cm
Les and Paula Presmyk specimen, J. Scovil photo.

The Rest of the Fun

As I write every year in my RMS posts, a lot of the best of Rochester occurs beyond the talks – in the halls, over meals, and on the 4th floor (the dealer floor, open when talks are not on).  Socializing continues well into the morning hours each night, and includes a few traditions – among others, the not-to-be-missed Saturday night mineral songs with David Joyce. (I assume most have heard Dave’s mineral collecting and mining tunes, but if not, I’m including a link below).
The collegiality at the RMS is unique among mineral events!

Displays

The Exhibit Room had great displays this year, as every year. Some are contributed by museums and many are contributed by collectors attending the RMS.

Terry Huizing Calcite Display, Rochester 2017

Calcite, Terry Huizing collection.
Amazing variety in this case.

As a reader, I often find it hard to take in many full-case displays in photos,  so here are just a few of the specimens that really struck me.

This brilliant bournonite in John Betts’ case has truly gorgeous twinning.

Bournonite, Yaoganzian Mine, John Betts collection

Bournonite, Yaoganxian Mine, Hunan, China – 3.6 cm
John Betts collection.

A huge spinel from the classic New York locality featured in the display from the New York State Museum.

Spinel, Monroe, Orange Co., New York, New York State Museum, Steve Chamberlain Collection

Spinel, Monroe, Orange Co., New York – approx 15 cm
Steve Chamberlain collection at the New York State Museum.

Super quartz from Palermo No.1 – for all the world looks like a fine contemporary Brazilian quartz, with bright, glassy lustre not conveyed in the photo.

PalermoQuartz

Quartz, Palermo No. 1 Mine, North Groton, New Hampshire – approx 7 cm
Mined by Bob Whitmore. Maine Mineral and Gem Museum

A great nest of silver wires from Beaverdell, in George Thompson’s case.

Silver, Highland Bell Mine, Beaverdell, British Columbia, George Thompson collection

Silver, Highland Bell Mine, Beaverdell, British Columbia – approx 5 cm
George Thompson collection.

Two super specimens from John Medici’s case.

Celestine from Holloway Quarry, Fluorite from Auglaize Quarry
Celestine, Holloway Quarry, Newport, Michigan – approx 7 cm
Fluorite with Calcite, Auglaize Quarry, Junction, Ohio – approx 5 cm
John Medici collection.

This hematite took my breath away. It is spectacular! It was part of an excellent display case of hematite and goethite from the Diane Francis collection.

Hematite, Congonhas, Minas Gerais, Brazil, Diane Francis collection
Hematite, Casa de Pedra Mine, Congonhas, Minas Gerais, Brazil – approx 7 cm
Diane Francis collection.

David Joyce had a great case of Grenville minerals. I thought rather than include something you might be expecting, like one of Dave’s great titanites, fluorapatites or zircons, I’d opt for something we don’t usually see from the Grenville. This is a striking, bright yellow sphalerite crystal.

Sphalerite, Balmat, St. Lawrence Co., New York, David Joyce collection, formerly Bill Pinch collection

Sphalerite, Balmat, St.Lawrence Co., New York – approx 5 cm
David K. Joyce collection

This beautiful sphalerite was formerly in Bill Pinch’s collection, and he gave it to Dave as a gift, so it seemed particularly fitting to include as my last photo entry from the cases this year.

Bill Pinch

As mentioned above, the following is the full In Memoriam written by Steve Chamberlain and included at the beginning of the RMS Program Notes this year.

In Memoriam – Rochester Mineralogical Symposium

Bill Pinch passed away on April 1, 2017 from complications of earlier surgery. A reception will be held this year in Rochester, New York, to celebrate his life. Next February, there will be a memorial service in Tucson, Arizona. We will celebrate his many achievements next April at the 45th Rochester Mineralogical Symposium.

Bill was an elemental force in specimen mineralogy. One of his most significant achievements was the initiation of the Rochester Mineralogical Symposium. The First Annual Mineral Workshop was held 20-21 April 1974 at the Sheraton Inn in Canandaigua. Under the auspices of Mineral Section President, Kay Jensen, Bill and Dave Jensen served as co-chairmen this first year. The second workshop, now the Rochester Mineralogical Symposium, was held 17-20 April 1975 in the downtown Holiday Inn and was again co-chaired by Bill and Dave Jensen.

For the next ten years, Pinch served as convening co-chairman and helped build the Symposium into an internationally-recognized annual event, setting the highest standards for speakers, exhibits and congeniality. He initiated the annual What’s New in Minerals – still a popular Saturday morning part of the event. He also began the annual production of Program Notes. With the 13th RMS, formal leadership of the Symposium passed to others, but Bill continued to serve as an advisor. With his support, the Technical Session was added to the Friday afternoon program and important mineralogical works were reprinted, including Goldschmidt’s Atlas der Krystalformen and Beck’s Mineralogy of New York State, to name just a few.

At the 25th Symposium, Bill gave a keynote address, “50 Years of Mineral Collecting; 25 Years of the Symposium”.  The preceding year, the Symposium had donated the annual proceeds of its annual auction to the successful funding effort for the Canadian Museum of Nature to purchase the W.W.Pinch mineral collection, establishing another legacy.

Slowly, over the next decades, Bill drifted away from direct participation in the Symposium We were delighted by his attendance at the 43rd RMS on the occasion of Michael Bainbridge’s talk, “The William W. Pinch Collection at the Canadian Museum of Nature”. The coming book of the same title will be a fitting memorial to Bill’s success in assembling a world-class mineral collection.  Here we acknowledge our debt to Bill for his successful efforts in beginning and growing the Rochester Mineralogical Symposium. Godspeed.

2018 RMS

As I mentioned up top, RMS 2018 will be a little different – it will be dedicated to Bill’s memory, and it will include talks on several topics that were close to Bill’s heart – among them, Tsumeb, Rare Minerals and Fine Minerals. Stay tuned for updates, as arrangements are finalized.  The dates are April 19-22 ,2018.

Until Next Year…

The Rochester Symposium is a great event, that has seen many of Mineral World’s most prominent names as contributors. At the same time, the Symposium continues to embrace contributions from all levels in mineral collecting – it simply would not be what it is without everyone who contributes.

Of course, the Symposium could literally not happen without the dedicated efforts of the team who put it together – countless thanks to Steve Chamberlain (chair), Helen Chamberlain (registrar), and many others on the committee and those helping at the event and in the background, including Dan Imel, Carl Francis, Bruce Gaber, Brian McGrath, Bob Morgan, Betty Fetter, George and Susan Robinson, Quintin Wight, Elizabeth Von Bacho and Tom White. I hope I haven’t missed anyone!

And thank you to all of the speakers and photographers from this year, for all of your help with photos to share through this report.

Links and References

If you are seeking links for anything mentioned above, some of these may be of interest:

On Bill Pinch’s website, there are tabs for the In Memoriam and also Links (this latter includes three links, with a video produced after the Canadian Museum of Nature acquired his original collection).

Our amazing professional mineral photographers (who – of course – take photos of private collection specimens for individual collectors): Jeff Scovil and Michael Bainbridge 

The new book by Robert J. Lauf: Collectors’ Guide to Orthosilicates

The Adelaide Mining Company has lots more crocoite photos (mining and specimens available) on its website. The underground photos are in the History section – they really give a sense of how tight most of these pockets have been, and provides good context for how remarkably well the specimens have been collected and preserved.

David K. Joyce has written – and plays and sings, of course – the soundtrack for so many great times in minerals. The tunes are available on itunes and the CD is available from Dave – if you’d like to hear them, here is the page where you can listen.

When they are available, the 44th RMS Program Notes will be posted online here.

Posted by: Raymond McDougall on 02.28.2016 | Filed under: Latest, Recent Mineral Updates | Comments (0)

I’ve posted some vibrant specimens of chrysocolla pseudomorphs in the new Chrysocolla Update (click here).

Ajoite, Luputo Mine, Lubumbashi, Democratic Republic of the CongoChrysocolla, Luputo Mine, Lubumbashi, Democratic Republic of the Congo – 8.1 cm

Definitive identification of these specimens has been confirmed. The specimens from this find have been identified as chrysocolla by way of chemical analysis conducted by Dr. Hexiong Yang of the University of Arizona. A preliminary Raman spectroscopic analysis had led to the suggestion of an ajoite identification (which was posted on mindat), but the Raman for each of these minerals is very similar and was therefore inconclusive.

Ajoite, Luputo Mine, Lubumbashi, Democratic Republic of the CongoChrysocolla, Luputo Mine, Lubumbashi, Democratic Republic of the Congo – 8.7 cm

A couple of observations about these specimens lead me to believe there is some complexity to the formation history. In spots where the underlying pseudomorphs are incomplete, one can examine the cross-sections. Some of those cross-sections reveal that the malachite core is entirely gone (and seems to be chrysocolla), while others retain some malachite. In addition, upon close examination with magnification, one can see there are small malachites sprinkled about, meanwhile the chrysocolla “crystals” have a rather rounded appearance. I believe that the small chrysocolla aggregates themselves are related to the malachite, as pseudomorphs after the malachite. These specimens might in fact be “chrysocolla pseudomorphs after malachite, on chrysocolla pseudomorphs (partial and complete) after malachite pseudomorphs after azurite.” Doesn’t fit on a label so easily, but these are highly unusual and remarkable specimens.

Ajoite, Luputo Mine, Lubumbashi, Democratic of the CongoChrysocolla, Luputo Mine, Lubumbashi, Democratic Republic of the Congo
Field of view 1.0 cm

These are delicate specimens, with some growths that are thin. As a result, there are incomplete pseudomorphs on almost all I have seen – in fact some are either prominently or mostly without complete ones. These incomplete pseudomorphs actually help to guide our understanding of the specimen’s formation.

Ajoite, Luputo Mine, Lubumbashi, Democratic Republic of the CongoChrysocolla, Luputo Mine, Lubumbashi, Democratic Republic of the Congo
Field of view 1.0 cm

Ajoite, Luputo Mine, Lubumbashi, Democratic Republic of the CongoChrysocolla, Luputo Mine, Lubumbashi, Democratic Republic of the Congo – 5.8 cm

Ajoite, Luputo Mine, Lubumbashi, Democratic Republic of the CongoChrysocolla, Luputo Mine, Lubumbashi, Democratic Republic of the Congo
Field of view 1.3 cm

Posted by: Raymond McDougall on 02.23.2016 | Filed under: Latest, Mineral Shows | Comments (0)

I love arriving back in Tucson. Urban field collecting at its finest!

TucsonSunset

There’s an excitement about the Tucson shows – we all feel it.

A bit similar to the way a the Christmas tree each year is evocative of the fun of past Christmases, in Tucson we have our ornamental orange trees in the courtyard at the Hotel Formerly Known as The Inn Suites…

Oranges

The mornings at the start of Tucson 2016 were not quite tropical.

frost

 Palm trees through the frost on the car windshield.

 However,  the Tucson sun is great and by the afternoon there’s a warm sunlight casting shadows.

Tucson 2016

So, into the car and off to the shows all over town in search of fine minerals… but can I just make a small random observation first?

Our rental car flashed this at us regularly,  throughout the trip:

CarWarning

I’m sorry, but if your brain is not already subconsciously running this question in the background for you every day, you’re gonna have issues. Waiting until a car prompts the thought is inadvisable.

OK. I’m done. On to the minerals. (It’s safe to move.)

poolsideThe courtyard mineral localities beckon…

Minerals!

There were great mineral specimens in Tucson this year and this post is just a small glimpse of a few fun things I managed to acquire. Each of the following will be the subject of an update on the website over the coming weeks.

Let’s begin with a new find of gorgeous yellow fluorites from Morocco. These are from the classic fluorite locality, the El Hammam Mine, they are unusually sharp, yellow cubes.

The hue of these fluorites varies, depending on the light source (common for fluorite), from a warmer honey-yellow under halogen, to a slightly brighter yellow in daylight and even a bit bolder under cool-temperature LED lighting. (This effect is different with each specimen, some show it more and some less).

Fluorite, El Hammam Mine, Meknes, Meknes-Tafilalet Region, MoroccoFluorite, El Hammam Mine, Meknes, Meknes-Tafilalet Region, Morocco
Field of view 4.0 cm

Upon close inspection, many of the crystals contain delicate, fine-lined purple phantoms.

Fluorite, El Hammam Mine, Meknes, Meknes-Tafilalet Region, MoroccoFluorite, El Hammam Mine, Meknes, Meknes-Tafilalet Region, Morocco
Field of view 2.5 cm

This was not a large find, and I chose the best quality ones available – if you’d like to see more photos, they are in the Morocco Fluorite update (click here).

Next up is the amazing Milpillas Mine in Mexico. It’s no surprise that we are continuing to see more azurites, and a few other things are trickling out too, but this time I was particularly interested in the brochantites. There are not so many (certainly nothing like the azurites) but these are super for the species, and I found a few excellent ones available this year.

Brochantite

Brochantite, Milpillas Mine, Cuitaca, Mun. de Santa Cruz, Sonora, Mexico – 3.9 cm

Brochantite2

Brochantite, Milpillas Mine, Cuitaca, Mun. de Santa Cruz, Sonora, Mexico
Width of this group is 3.2 cm

A bit further away from home, there was a relatively small new find of axinite at Dalnegorsk, Russia. Of course, over the years, some beautiful axinite specimens have been found at Dalnegorsk, some have been identified as axinite-(Mn), some as axinite-(Fe), and I’m told that these ones are axinite-(Fe). As is always the case with axinite, it is incredibly difficult to obtain damage-free specimens, and most from this find did have chipping. However, a few were in superb condition!

Axinite-(Fe)Axinite-(Fe), Bor Mine, Dal’negorsk, Primorskiy Kray, Russia
Field of view approximately 4 cm

Also from the Dalnegorsk mining complex, a newer mine has produced some wonderful new calcite specimens. The Yushnoe Mine is a newer mine and to date has produced virtually no fine mineral specimens. In 2015, a pocket of calcite crystals contained some beautiful twins. This was not a large or prolific find at all, and I found almost no specimens were undamaged, but I did find them! They show excellent twinning, with the same form as the now-classic twinned yellow calcites from the Sokolovskoe Mine, Rudniy, Kazakhstan. Beautiful!

YushnoeCalciteCalcite, Yushnoe Mine, Dal’negorsk, Primorskiy Kray, Russia
Field of view approximately 3.5 cm

From Canada, a recent expedition to Rapid Creek, Yukon, produced some fine lazulite specimens. This is a very remote locality and collecting there is so expensive that it is rarely undertaken these days. Many specimens from the find debuted in Tucson, and we (David K. Joyce and I) acquired the finest.

Lazulite2

Lazulite, Rapid Creek, Dawson Mining District, Yukon, Canada
Largest crystal 1.5 cm

Lazulite1Lazulite with Kulanite, Rapid Creek, Dawson Mining District, Yukon, Canada – 5.7 cm

One of the great things about Tucson is of course the chance to reconnect with mineral friends and colleagues from all over the world, and sometimes they have brought some pretty amazing things along with them. Not all of these are new finds by any means, but sometimes some remarkable specimens surface in Tucson.

One such find was strontianite from an Austrian collection. Strontianite is a relatively common mineral, but great specimens are not common. Typically when we think of the mineral strontianite – let’s face it, IF we even think of it at all – we think of fuzzy-looking aggregates of tiny crystals or relatively unattractive specimens. Perhaps that’s not fair (sorry strontianite!) and there are of course exceptions, including a small number of specimens from Scotland, Illinois and the Alps. And some of the finest strontianite crystals in the world come from Oberdorf an der Laming, Laming valley, Bruck an der Mur, Styria, Austria. The crystals occur in a variety of habits, with quartz-like prisms, blocky hexagonal prisms and elongated dogtooth-style crystals. I was very happy to have found a small suite of exceptionally well-crystallized strontianites from Oberdorf an der Laming in Tucson.

StrontianiteStrontianite, Oberdorf an der Laming, Laming valley, Bruck an der Mur, Styria, Austria
Crystal 1.2 cm

Strontianite2Strontianite, Oberdorf an der Laming, Laming valley, Bruck an der Mur, Styria, Austria
Field of view approximately 3.5 cm

Strontianite3

Strontianite, Oberdorf an der Laming, Laming valley, Bruck an der Mur, Styria, Austria
Field of view approximately 2 cm

Another great thing about reconnecting with everyone in Tucson is the chance to learn from mineral friends. You know, we all end up with these specimens from all over the world, and then we take them back to our little lairs, and inevitably we have more work done on them. So there are always new finds, identifications, and re-identifications of minerals.

In Tucson this year, I learned that last year’s find of super tetrahedrite crystals at the Mundo Nuevo Mine was in fact a find of crystals of tennantite. Of a large number of specimens tested at Harvard, only one turned out to be tetrahedrite. Almost all turned out to be tennantite (a small number were intermediate, tennantite-dominant). Which is fun – they were already great tetrahedrite, but they are super for tennantite. I have a few left and although they are presumably tennantite, I have taken them off the site pending confirmatory analysis, and then they will be back on. For those of you who might not have seen them when I posted them originally, they are sharp and lustrous – here are a couple.

100740(2)(fov4.0)

Tennantite, Mundo Nuevo Mine, Huamachuco, Sanchez Carrion Province, La Libertad Dept., Peru
Field of view 4.0 cm

100742(1)(8.2)Tennantite, Mundo Nuevo Mine, Huamachuco, Sanchez Carrion Province, La Libertad Dept., Peru – 8.2 cm

Related to this finding, it was also discovered that there are some tennantite specimens with the rare mineral lautite on them. These are microscopic crystals and rosettes – a mineral that is rarely found at all, let alone in crystals. Here’s a photo. (By the way, Dave still has a few of these lautites available on his website – I’m including a link to them at the end of this post, if you are interested.

lautite

Lautite, Mundo Nuevo Mine, Huamachuco, Sanchez Carrion Province, La Libertad Dept., Peru
Field of view 2mm.
David K. Joyce photo.

Speaking of identifications, one find that first came to light last year has turned out to be something special. Last year you may have seen (and may even have acquired) specimens of “chrysocolla over malachite pseudomorphs after azurite” from the Luputo Mine, Lubumbashi, Democratic Republic of the Congo. Thanks to analysis conducted by Dr. Hexiong Yang at the University of Arizona, we now know they are in fact not chrysocolla, but ajoite. This is a remarkable development – ajoite has not been known in display specimens, so this is a first! (Ajoite is best known from the ajoite-included quartz crystals from Musina, South Africa).  I was very happy to be able to acquire a few of these specimens in Tucson!

Ajoite2Ajoite over Malachite pseudomorph after Azurite
Luputo Mine, Lubumbashi, Democratic Republic of the Congo
Field of view 3.5 cm

Ajoite3

Ajoite over Malachite pseudomorph after Azurite
Luputo Mine, Lubumbashi, Democratic Republic of the Congo
Field of view 2.5 cm

Tucson Beyond the Minerals

I’ll spare you the stories of all of the great get-togethers with mineral friends, but I’d like to share a couple.

Canadian collector and dealer Ray Hill hosts fun dinners at his rented place in Tucson each year. Not only is he a great cook, but he also assembles such good groups together that it is always both interesting and a good time. The group included Ray Hill, David Joyce, John Montgomery, Marie and Terry Huizing, David Wilber and Larry Venezia. I wish I had a photo from this evening’s highlight, but it was too dark out to capture the mood without a proper camera setup. Ray had brought a portable propane campfire from Canada. (Never seen one before…) After dinner we moved outdoors… and what is a campfire without a song or two?  Many of you know that David Joyce has written, and plays and sings, great mineral songs (link at the end of this post) – so Dave brought out his guitar and we had good fun singing mineral songs around our Tucson campfire under the stars.

The other one I’d like to share is a photo from a dinner we look forward to every year, with Si and Ann Frazier, and Frank and Wendy Melanson. Always a fun evening, with good food, stories, laughs, and some mineral show-and tell, so it’s hardly a time that prompts serious reflection (!). However when I was looking at this photo afterward, I was struck by the knowledge and experience in this room. You are looking not only at five of the most knowledgeable mineral people out there, but the five people in this photograph have been responsible, directly and indirectly, for the preservation and placement of uncounted tens of thousands of the world’s fine mineral specimens into museums and private collections.

Dinner

From left to right, Si and Ann Frazier, Wendy Melanson, David K. Joyce and Frank Melanson

Although we all wish Tucson would never end, somehow it ends too soon every year…

Last Light

Last sunlight, as Tucson shadows fall

Happy to be back home, to the forest shadows…

Snowshadows

… and where the snow crunches underfoot with each step in the winter woods.

Final Snowshadow

Links

(1) For the lautite specimens at davidkjoyceminerals.com, click here.

(2) For the mineral songs click here (“The Mineral Dealer” is an awesome song for Tucson season.)

Posted by: Raymond McDougall on 05.23.2015 | Filed under: Latest, Recent Mineral Updates | Comments (0)

 

I’ve made no secret of my belief that excellent black crystals are very cool. But colour is great too, and the latest update has lots! The new DR Congo Update (click here) features some amazing hues of pink in beautiful specimens of cobaltoan dolomite from Katanga, some of which have green malachite in association. The update also includes a specimen with exquisite twinned calcite crystals from Mashamba West.

Dolomite, var. cobaltoan dolomite, Katanga, Democratic Republic of the CongoDolomite, var. cobaltoan dolomite with malachite, Katanga, Democratic Republic of the Congo – field of view 3 cm

Dolomite, var. cobaltoan dolomite, Katanga, Democratic Republic of the CongoDolomite, var. cobaltoan dolomite, Katanga, Democratic Republic of the Congo – 7.3 cm

Dolomite, var. cobaltoan dolomite, Katanga, Democratic Republic of the CongoDolomite, var. cobaltoan dolomite, Katanga, Democratic Republic of the Congo  – 8.5 cm

Dolomite, var. cobaltoan dolomite, Katanga, Democratic Republic of the CongoDolomite, var. cobaltoan dolomite with malachite, Katanga, Democratic Republic of the Congo – field of view 3 cm

Dolomite, var. cobaltoan dolomite, Katanga, Democratic Republic of the CongoDolomite, var. cobaltoan dolomite, Katanga, Democratic Republic of the Congo – 5.9 cm

Dolomite, var. cobaltoan dolomite, Katanga, Democratic Republic of the Congo

Malachiteon dolomite, var. cobaltoan dolomite, Katanga, Democratic Republic of the Congo – field of view 2.4 cm

Dolomite, var. cobaltoan dolomite, Katanga, Democratic Republic of the CongoDolomite, var. cobaltoan dolomite, Katanga, Democratic Republic of the Congo – field of view 2 cm

Calcite on chrysocolla, Mashamba West Mine, Kolwezi, Katanga, Democratic Republic of the Congo

Calcite twins on chrysocolla, Mashamba West Mine, Kolwezi, Katanga, Democratic Republic of the Congo – 4.1 cm