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Posted by: Raymond McDougall on 03.30.2018 | Filed under: Latest, Recent Mineral Updates | Comments (0)

 

I’ve added excellent specimens from two great Peruvian localities in this Peru Update (click here) – tennantite specimens from Mundo Nuevo and pyrite specimens from Huanzala.

The Mundo Nuevo tennantites are excellent specimens for the species. Mined during 2014-15 specimen recovery work, they are part of a find that has now been analyzed quite extensively. Of those (over 40 specimens tested) all were tennantite except one that was a borderline tennantite-tetrahedrite. Accordingly, specimens from this find are now labelled tennantite. I have not had each of these analyzed, given the pervasive tennantite results (and not wanting to add to their prices by incurring unnecessary cost). These tennantites were originally posted on this website labelled “tetrahedrite”, as they were sold to me under that label – they were then removed from the site until the analysis work on the find had been completed.

Tennantite, Mundo Nuevo Mine,  Mine, Huamachuco, Sanchez Carrion Province, La Libertad Dept., Peru

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

Tennantite, Mundo Nuevo Mine,  Mine, Huamachuco, Sanchez Carrion Province, La Libertad Dept., Peru

Tennantite, Mundo Nuevo Mine, Mine, Huamachuco, Sanchez Carrion Province, La Libertad Dept., Peru – 8.1 cm

Tennantite, Mundo Nuevo Mine,  Mine, Huamachuco, Sanchez Carrion Province, La Libertad Dept., Peru

Tennantite, Mundo Nuevo Mine, Mine, Huamachuco, Sanchez Carrion Province, La Libertad Dept., Peru – 8.0 cm

Tennantite, Pyrite, Mundo Nuevo Mine,  Mine, Huamachuco, Sanchez Carrion Province, La Libertad Dept., Peru

Tennantite, Pyrite, Mundo Nuevo Mine, Mine, Huamachuco, Sanchez Carrion Province,
La Libertad Dept., Peru – 7.6 cm
The pyrite specimens from Huanzala are particularly high quality ones I’ve acquired individually in recent years, including a couple acquired in Peru.
Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru
 Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru – 6.5 cm
102142(1)(7.1)
 Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru – 7.1 cm
Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru
 Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru
Field of view 6.0 cm
 Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., PeruPyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru – 11.5 cm
Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru
Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru – 7.5 cm
Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru
Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru – 6.3 cm
Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru
 Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru – 5.0 cm
Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., PeruPyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru – 5.3 cm
Pyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., PeruPyrite, Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Dept., Peru – 5.6 cm
Posted by: Raymond McDougall on 02.23.2018 | Filed under: Latest, Mineral Shows | Comments (0)

 

It’s hard to believe that another Tucson has come and gone already. In the middle of a cold Bancroft winter, Tucson’s wonderful warm sunshine was sure welcome.

Santa Rita Foothills, Arizona Santa Rita Foothills, southeast of Tucson

I was very fortunate to be able to experience Tucson’s natural surroundings this year. I stayed with my good friend and collecting partner David Joyce (David K. Joyce Minerals), with Carol Teal and their dog Riley at their new place in the beautiful Santa Rita Foothills, southeast of the city.

DaveRiley2

 Dave and Riley on their sitting rock

In the foothills

Photo of me taken by Don Doell – Santa Rita Foothills, with Tucson in the distance

The Sonora Desert is a remarkable place in the world. In places, and at many times of year, it appears harsh and unforgiving. As to flora and fauna, the Sonora Desert gives the superficial impression that it is inhabited only by the hardiest very few species.

Saguaro SceneSaguaro Cacti

Immerse yourself in it a little, and the truth reveals itself – the variety of plants and animals is amazing (600 plant species and 200 animal species).  As with everything in life, the more quiet observation you do, the more you see. The foothills and desert areas around Tucson are full of life.

Deer 1

Deer paying a visit to Dave and Carol’s place

Cactus flower

Cactus bloom

Saguaro armSaguaro arm

On one of our mornings in the desert, the moon put on a show of its own.

Mesquite EclipseUnder the mesquite trees with the lunar eclipse before dawn, Santa Rita Foothills

The Minerals

OK OK. I know, we all really want to read about minerals. Of course, what Tucson means is the fun of midwinter urban field collecting, and there were lots of great specimens this year.

Some beautiful and interesting specimens have continued to come from Pakistan and Afghanistan. From Pakistan, the recent brucite specimens are super – some of the finest brucite I’ve ever seen. The Killah Saifullah brucite were first noted to me by John White after he saw a couple in Munich, 2016, and since then, the quality of the finest has greatly increased over those early days. It seems that most of these are occurring in very tight seams, or with a fragmented or brecciated matrix, and so most have contacts and grey spots around them. The colour of most of them is a cream-to-very-pale-yellow, but the best have a bright yellow hue. Many are very finely crystallized, but on some, like these ones, one can easily see many crystal faces. These Pakistan brucites are amazing for the mineral.

I’ve done my best to colour-balance them accurately (daylight, shade). I always do that anyway, of course, but some mineral specimens are susceptible to really skewing away from daylight appearance when photographed.

Brucite, Killa Saifullah, Balochistan, Pakistan
Brucite, Killa Saifullah, Balochistan, Pakistan – 6.1 cm

Brucite, Killa Saifullah, Balochistan, Pakistan

Brucite, Killa Saifullah, Balochistan, Pakistan – 7.2 cm

Brucite, Killa Saifullah, Balochistan, PakistanBrucite, Killa Saifullah, Balochistan, Pakistan – 3.2 cm

From Afghanistan, a small number of excellent specimens have continued to come from some of the best-known occurrences, and I just want to highlight one in particular. From Sar-e Sang, Dudley Blauwet has recently brought out a couple of particularly excellent diopside specimens, and I am including one here. Given that diopside is not an uncommon mineral, it’s surprising that great matrix specimens are so hard to find. This one is striking.

102113(1)(8.0)
Diopside, Ladujar Medam, Sar-e Sang River, Kokcha Valley, Badakhshan, Afghanistan – 8 cm

Moving on to South America, there have been a couple of particularly interesting new finds. In Potosí, Bolivia, there has been a discovery of very pretty amethyst crystals. There isn’t more specific information about the locality at this time – I’m told that this is because it is in an unnamed area of Potosi, not near to any named settlement or geographic feature. The specimens were discovered by farmers, at the edge of a field area, bordering hills. These have somewhat similar habit and appearance to some of the amethyst crystals from Peidra Parada (Las Vigas), Mexico. They are sharp, with top lustre and excellent transparency. Some are doubly-terminated, and some show a great reverse-sceptre habit. These are really sweet – I only found them available from one person, and I acquired the nicest for the website.

Quartz, var. amethyst, Potosi, BoliviaQuartz, var. amethyst, Potosí, Bolivia – 5.3 cm

Quartz, var. amethyst, Potosí, Bolivia

Quartz, var. amethyst (reverse sceptre), Potosí, Bolivia
Field of view 1.5 cm

Quartz, var. amethyst, Potosí, Bolivia

Quartz, var. amethyst, Potosí, Bolivia
Field of view 2.5 cm

In Peru, there has been a new discovery of clinozoizite. I understand that the workings from which these were produced are only operational on a sporadic basis. The specific zone from which these specimens were recovered is apparently now done, and they have encountered a bit of epidote as the work has advanced. Excellent display specimens of clinozoisite are generally uncommon – one thinks of the famous finds at Alchuri in the Shigar Valley in Pakistan, and few other localities come to mind. These clinozoisite specimens are all clustered groups of crystals. I have seen no single isolated crystals. The crystals themselves are very sharp and well-defined, lustrous, with some twinned and some not.

Clinozoisite, Cerro San Cristobal, San Vincente de Canete, Canete Province, Lima Dept., Peru

Clinozoisite, Cerro San Cristobal, San Vincente de Cañete,
Cañete Province, Lima Dept., Peru – 4.3 cm

Clinozoisite, Cerro San Cristobal, San Vincente de Canete, Canete Province, Lima Dept., Peru Clinozoisite, Cerro San Cristobal, San Vincente de Cañete, Cañete Province, Lima Dept., Peru

Clinozoisite twin, Cerro San Cristobal, San Vincente de Cañete,
Cañete Province, Lima Dept., Peru – 3.5 cm

Clinozoisite, Cerro San Cristobal, San Vincente de Canete, Canete Province, Lima Dept., Peru Clinozoisite, Cerro San Cristobal, San Vincente de Cañete, Cañete Province, Lima Dept., Peru

Clinozoisite twin, Cerro San Cristobal, San Vincente de Cañete,
Cañete Province, Lima Dept., Peru – 8.6 cm

I want to highlight one other great find that is relatively recent – the spectacular iron-cross twins of pyrite from Gachalá, Cundinamarca, Colombia, discovered about a year ago (I believe the ones available in Tucson were from the original find, as opposed to new production). The term “iron-cross twin” refers to twinned pentagonal dodecahedra, the edges of which cross at right angles. Well-defined iron-cross pyrite twins have always been uncommon and sought-after. Most are small, and often incomplete. These are quite large for iron-cross twins – they are pretty spectacular. One note about these: they have been mislabeled as goethite or limonite after pyrite. They are not pseudomorphs. In fact, they are pyrite, with a very thin surface layer of goethite.

Pyrite Iron Cross Twin, Gachalá, Cundinamarca, Colombia

Pyrite Iron-Cross Twin, Gachalá, Cundinamarca, Colombia – 5.0 cm

Over to Africa, some great specimens. In Tanzania, the Merelani occurrences continue to produce very fine specimens of a number of minerals, while a few specimens from finds in recent years have surfaced as well.

Merelani Diopside

 Diopside with graphite, Merelani Hills, Lelatima Mountains, Manyara, Tanzania – 3.7 cm

MerelaniPrehnitePrehnite, Merelani Hills, Lelatima Mountains, Manyara, Tanzania – 5.3 cm

From the finds in 2012-13, I managed to acquire a world-class alabandite crystal.

Alabandite, Merelani Hills, Lelatima Mountains, Manyara, Tanzania

Alabandite, Merelani Hills, Lelatima Mountains, Manyara, Tanzania – 6.8 cm

From Malawi, there have been more first class specimens available from the the occurrences at Mt. Malosa and Mulanje, including arfvedsonite, eudidymite and zircon.

Zircon, Mount Malosa, Zomba District, Malawi Zircon, Mount Malosa, Zomba District, Malawi – crystal 3.2 cm

Over the years, the very well-known almandine occurrence at Vrondolo, Madagascar, has produced some unusually fine crystals. This occurrence is a fair distance up a small mountain – it takes hours to reach it on foot. Most often, the crystals from here are slightly to heavily chipped when extracted, because they are found frozen in solid rock. However, I found a small recent group of specimens including crystals that grew into open spaces, as well as other crystals extracted in super condition. These are really nice garnets!

Almandine, Vorondolo, Antananarivo, Madagascar

 Almandine, Vorondolo, Antananarivo, Madagascar – 4.5 cm

Last from Africa, Morocco continues to produce excellent specimens of many minerals – the golden age of Moroccan minerals continues. Because these finds have been known generally or written up by others, I won’t dwell too much on them in this report – there will be many fine Moroccan specimens coming on the website over the next few months. However, I want to highlight some Imilchil material that I think is noteworthy. For some time, we have seen small dark garnet crystals from Imilchil. Some of these crystals have been found to be the titanium-rich garnet group member, schorlomite, while I’m told most analyzed specimens are actually titanium-rich andradite, not enough titanium to be schorlomite. A new find at Anemzi (the same Imilchil-area locality that produces the fine green fluorapatite crystals, and has produced nice magnetites) has produced some of the nicest of these dark andradite crystals I have seen from Imilchil. At their finest, the crystals are sharp with beautiful morphology, and a good number of the specimens are comprised of a stack of these crystals. Some specimens have small, sharp, octahedral magnetite crystals in association – they are sparse, but a neat pairing. Independent from the andradites, Anemzi has produced some sharp magnetites lately as well, making for very nice specimens.

Andradite, Anemzi, Imilchil, Er Rachidia, Morocco

Andradite, Anemzi, Imilchil, Er Rachidia, Morocco – 7 cm

Andradite, Anemzi, Imilchil, Er Rachidia, Morocco

Andradite, Anemzi, Imilchil, Er Rachidia, Morocco – 3.5 cm

Magnetite, Anemzi, Imilchil, Er Rachidia, Morocco

Magnetite, Anemzi, Imilchil, Er Rachidia, Morocco – 4.4 cm

My final mineral entry is from China. I feel that the find of fluorite from Fujian deserves a mention, even though China has produced so much fluorite over the years. These new ones are the fluorites that have been dubbed “tanzanite fluorite” by several dealers. These have been available since early 2017, and they were not widespread this year at Tucson. The ones available were quite expensive. This locality has produced a range of fluorite – the most tanzanite blue-purple is from the one 2017 find, while other blues and purple hues have been recovered as well. I’ve been told there is “no more” – of course!!! – and we’ve all heard that so many times before, so skepticism is certainly warranted! I personally will believe it when I see it. However, I didn’t see as much as I expected and hoped, so we’ll see. Moreover, most of the specimens I did see were significantly contacted and/or damaged. I believe this is not only reflecting the way they were collected (perhaps in some cases with less care than we’d like), but also due to the nature of the occurrence. Many of these seem to have formed in very tight and narrow spaces, and would have been exceptionally difficult to extract without any contacting issues. I think the overall story of this locality will be clearer over time. Given that there are several colour hues and crystal habits from this locality, so it seems likely there was more than one pocket. These are beautiful fluorite specimens!

Fluorite, Xiayang, Yonchun Co., Fujian, China

 Fluorite, Xiayang, Yongchun Co., Fujian, China – 5.3 cm

Fluorite, Xiayang, Yonchun Co., Fujian, China

Fluorite, Xiayang, Yongchun Co., Fujian, China – 3.4 cm

Fluorite, Xiayang, Yonchun Co., Fujian, China

Fluorite, Xiayang, Yongchun Co., Fujian, China – 5.2 cm

A Remarkable Emerald

My friend John White came upon a remarkable emerald specimen from Pakistan and I want to share a photo. I’ve never seen anything like it, and much more important, John (you likely know, the former curator of the Smithsonian Institution’s mineral collection) has never seen anything like it! It is available.

Beryl var. Emerald - Pakistan 28-1-25

 

 Beryl, var. emerald, Guijar Kalay Valley, Swat District, Khyber Pakhtunkhwa, Pakistan.
The larger crystal is 3.5 cm tall.

Friends

Tucson 2018 was a great time, with lots of great friends and the beauty of the Sonora Desert. Thank you all!

3 shadows

Evening shadows  (I believe the order is Don Doell, me, John Betts)

Mineral Song Campfire

Mineral songs around the campfire, led by Dave (of course!)
From left: Malcolm Southwood, John Veevaert, John Betts, Don Doell, David Joyce and Angela Southwood

Thank you again Carol, Dave and Riley, for a wonderful time!

Carol Dave Riley

Until next year, so long, Tucson…

Palo Verde Sunset

Home! And… Rudy!

As great as it was, it’s wonderful to be home. The warm sun of the Tucson desert having recharged me, I’m happy to be back out in the winter woods.

Snowy Road, Bancroft, OntarioOur snowy woods, near Bancroft, Ontario

SnowWoods 2

Sunny winter morning, Bancroft, Ontario

And as many of you know, this means I’m back to once again sharing fun with young Rudy, our Labrador Retriever puppy.

Rudy McDougallDad, can I join you on the couch?

Rudy McDougall

First shipping run to Bancroft.
Dad, I’ll drive.

In only a couple of months he has transformed from tiny puppy to young dog. He’s gleeful about pretty much everything.

Rudy McDougallSnow? Love it!

Rudy is of course new to all this mineral business. Our founding Labrador Retriever, Emery, supervised all operations – he was the Chairman of the Afternoon Snooze Committee and comprised our IT Department, although he slept through most of our business operations. It will be a while until Rudy is ready to step into Emery’s higher roles, but he is a great little supervisor. For now, he is happy to be a particularly active part of all packing, shipping and particularly unpacking operations. He has delighted in founding our Playful Mayhem Department.

Rudy McDougall

What do you mean, my office chair is for “sleeping” while you work?

With lots of Tucson minerals to come, Rudy and I will do our best to get them online over the next few weeks!

Posted by: Raymond McDougall on 02.13.2014 | Filed under: Adventurers, Latest | Comments (0)


Into the Andes

The Road to Quiruvilca

You might think that a career working with mining companies and executives around the globe was surely a ticket into countless famous mineral localities everywhere. Oh, if only. (In fact, of the thousands of active mining and exploration projects worldwide, most are not famous mineral localities, nor do they produce anything approaching fine mineral specimens.)

So when my friend Adolfo Vera called me at home late one cold December night to talk – in his capacity as President of Southern Peaks Mining Company – about a new deal, I could hardly contain my enthusiasm. (Ok let’s be honest, I didn’t actually try to contain it.)

Adolfo: “Ray, can we talk about negotiating the purchase of a mine in Peru? You may never have heard of it – it’s called the Quiruvilca Mine.”

Ray:  “Umm… I’ve more than heard of it…” (After all, it is one of the most important mines in Peru’s history, famous among mineralogists and collectors for fine specimens of many minerals.)

Adolfo laughed and responded that if we were successful, I was welcome to catch the next plane and he would love to host… and when we did finally close the deal, I took Adolfo up on his kind offer and set off on an adventure to Quiruvilca with my collecting partner David Joyce (www.davidkjoyceminerals.com).

A trip to Quiruvilca is a bit involved. Like many of Peru’s most famous polymetallic mines, Quiruvilca is high in the Andes. After a flight to Trujillo, the drive from sea level takes a few hours, beginning among sugar cane plantations.

Sugar Cane

The main highway services not only Quiruvilca, but other towns and mining developments, including Barrick’s Lagunas Norte (Alto Chicama) project.

Books

Although construction and improvements continue on the road, it was still a treacherous affair at the time of our visit. (A week later, a bus with 60 people crashed off of this same road into the river gorge, killing all on board.) The highway is full of large vehicles with interesting cargo.

Highway 2

And this main highway gets messy during the rainy season…

Highway 1

Traffic is all over the road. Coming around one corner, this is the view out the front  window. (Yes, the front.)

Highway 3

In part, vehicles are all over the road because of the potholes. You can see a few small ones in the photo above, but here is a view of larger ones – each one enough to swallow even a tanker truck.

Highway 4

The highway climbs up and up, into the Andes. Many afternoons in the rainy season all you get are glimpses across the mountains through small holes in the clouds.

Mountains in the Clouds

Once you get to Quiruvilca, you have climbed to an altitude of 3800 metres (12,500 ft). By the way, the name “Quiruvilca” means “sacred tooth” in the Quechua language, and refers to this formation (photo below) which rises off the top of the mountains into the sky (and which is actually a few kilometres away from the town and mine).

Tooth

Company Area

Upon arrival at the Quiruvilca Mine, we were invited to stay at the nicest residence within the gated executive housing area, near the company offices and labs. A wonderful place to stay, this complex dates to the time when Asarco owned the mine. (As the town of Quiruvilca developed as a typical mining company town, I am not sure if there would even have been any public accommodations, had we been independent visitors and not guests of the mine). As it was, we were spoiled.

Housing 1

Our house had a nice fireplace (helpful, as it was chilly during our stay, between 4 and 10 degrees C).

Housing 3

In the vicinity of the housing area and the company offices, there were trees, and yet you could still catch glimpses of the valley and mountains beyond.

Housing 2

Looking back at it all from the hills across the valley, the view includes the mill at the top, the company offices in the middle section of trees and our housing area was in the group of trees below and to the right of the middle of the photo.

Mill and Complex

Looking at the above photo for context, the Quiruvilca Mine and the town of Quiruvilca are still further up the valley (to the left in the above photo – and the highway from Trujillo comes in from the right in the above photo). A mountain scene with the mill and company complex was visible from higher up the valley by the water tower, above and just beyond past the town and mine.

Watertower

Town of Quiruvilca

The town of Quiruvilca packs a lot in – there isn’t much unused space.

Q 7

Rocks are sometimes used to add extra weight to the roofing material.

Q 1

We had a look around the central area – this little guy took a good look at us, but wasn’t inviting us for a drink.

Q 5

Sunny breaks brought people outdoors again and the sun highlighted some of the colour in the streets.

Town1

Q 2

Many of the structures and houses date back to earlier times in the life of the mining town.

Q 3

The Quiruvilca Mine

The Quiruvilca Mine is an amazingly large complex of mining operations. Although mineralization was first discovered at Quiruvilca in 1789, commercial mining did not commence until the beginning of the 20th century. The mine has produced copper, gold, silver, lead and zinc – the latter three are key in the current operations. The workings consist of several different access adits leading underground to labyrinthine networks of tunnels, raises and stopes on many levels. These workings are so extensive, having been developed and worked continuously since 1907, that no-one was able to say for sure how many kilometres of workings there are underground. A guess from having been shown the maps and plans (including the areas that are now flooded) is that there could be between 100-200km of tunnels, and possibly even more.

Although working in these kinds of mines is dangerous, the company has rigid and extensive safety rules and regulations in place. When we arrived at Quiruvilca on our first night, we were immediately given a full session of safety training and testing – about two hours’ worth. We also had a visit that night with the company doctors for testing – which came in handy later for me when the altitude got me! These high altitude mines – particularly those with legacy workings like Quiruvilca – can be tricky places, and running one safely is a complicated business.

Part of the mine is serviced by the headframe over the Elvira shaft – the Pique Elvira. I thought I’d convey the feeling of being there in a black and white photo.

Elvira

Today, mining at the Quiruvilca Mine involves small teams working stopes all over the workings – at any given time, approximately 60 separate stopes are producing and contributing to the ore going to the mill. When you think about it, this is an amazing amount of active development of headings at any given time! A total of nearly 1000 people work at the Quiruvilca mining/milling/office complex.

As for the mine itself, many of the tunnels are timbered, and some of them are constructed to accommodate rail cars to haul the ore.

Tunnel1

The timbers are replaced every two years (water weakens them over time) and the rails are replaced approximately every 6 years.

Outside the adits, the ore cars are emptied – the photo below shows ore cars outside the Morrococha adit, with the Pique Elivira in the background on the hill.

Tunnel2

Going Underground

We received detailed explanations of the workings from senior geologist, Edgar. Note all the timbers stacked on the right. We had the chance to visit a few zones in our time at Quiruvilca.

UG1

Underground, the tunnels and galleries are supported with timbers at various places – the walls are also bolted and caged in places. Some of the areas worked in the past are still visible from active areas. (Small note: you will notice bright spots in the underground photos – this is dust reflecting the flash on my camera – there is a lot of dust in the air underground when nearing active areas of the mine.)

UG2

After walking for perhaps 1.5km underground, we arrived at the raise – a series of ladders to be climbed to get to the working stope.

UG3

Up the ladders…

UG4

And at the top, we arrived at an actively working stope.

Stope1

Significant amounts of woodwork have been put in place where the walls have little structural integrity – but even in these places it was possible to see minerals. The next photo below is a pocket that contained chalcopyrite and tetrahedrite – interesting, and some micro crystals but nothing that would be considered a fine mineral specimen.

Stope2

We were taken to several working faces and given a chance to look for specimens. Senior geologists and supervisors joined in helping with our visit, and we could not have been given a better introduction to Quiruvilca.

UG5

Dave with senior geologist, Jose.

UG6

Between Dave and me is Mauro, senior supervisor in the Moroccocha workings, who led us up ladders into working stopes for collecting.

As mineral specimens go, being at Quiruvilca is similar to most mineral localities – you have to be in exactly the right place at exactly the right time, if you are to find fine specimens. If you stop and think about it, if the mine has 60 working faces operating for 365 days a year, the few specimens that you do see come from Quiruvilca each year come from all of that ongoing work. You would have to be in 60 places at the right time, every day, all year long, so that you were in the right place for the few fine specimens that are actually encountered. Doesn’t bode well for one’s chances on a short visit! (even though the company geologists did their best to take us to the places they felt would have the best chance on the days of the visit). We had a great time and found a few interesting small reference specimens, but that was all that was possible on this visit. We were able to examine the walls, collect what we found, and it was a super experience.

UG7

View of the sulfide veining at a working face.

As you can see, there aren’t exactly pockets gaping with crystals. In fact, the rock in the mineralized zones includes a lot of very soft material with poor competence – it just crumbles. As soon as the stope face has advanced, new timbers are put in place to support the walls. (Walking up the stope you simply climb over or under these.)

UG8

All along the stope, the sulfide-sulfosalt mineralization is evident.

UG9

Seeing lots of chalcopyrite-tetrahedrite veining, but sadly I’m not seeing any pockets or vugs here! (D.K. Joyce photo.)

Tunnel3

Underground, we waited for the lift to return us up the shaft for the hike back out.

About that Altitude…

An elevation of 3800 metres may not sound that high. With no snow and no jagged peaks, it certainly didn’t look as if we were in thin air. But if you drive that whole ascent  in a short few hours, and then dive into hiking with backpacks up and down mine ramps, and maybe add in a nice big dinner… I didn’t react that well. Two of my best friends at the mine were Miguel, the company doctor, and Mr. Oxygen Tank. Miguel grounded me from any collecting at all on Day 2 (bummer!) after I woke up in the middle of the overnight with crazy racing breathing (it was easier to breathe standing up than lying in bed (!)). They take the altitude issue very seriously – for example, once I mentioned to our house hostess Marina that I had had a small issue breathing overnight, an ambulance was at the house in under 2 minutes. And to go to the medical office for some oxygen that first morning, I felt I could easily walk, but that was refused – ambulance only. No chances are taken! With oxygen and some adjustment time, I was able to be more active after that, and was obviously more cautious, but for those of us who do not live at altitude, that rapid ascent is not for the faint of heart. Fortunately, Quiruvilca is a dry camp – had I had wine with that first dinner, I’m sure my issue would have been compounded.

Quiruvilca Geology

Excellent references include a discussion of the geology at Quiruvilca (see the list at the end of this post). As a basic overview, the geology is Miocene age – very recent in geological terms (the Miocene period is from approximately 23 to 5.3 million years ago). The host rocks are a mix of andesites, basalts and dacites, and the mineralization is concentrated in mesothermal and epithermal veins. The key to understanding the occurrence of the minerals at Quiruvilca is the classification of the four mineral zones, along with the occurrence of the vein structures.

The map below (provided by the company) gives an overview of the four zones – and note the veins (“vetas”) indicated as red lines.

Map1

The inner (orange) zone is referred to as the Enargite Zone. At one time, mining was concentrated entirely in this zone, and the workings here are extensive, though many are now flooded. This zone produced enargite, pyrite, chalcopyrite, galena, sphalerite, wurtzite, tennantite, the famous orpiment specimens, realgar, and the world’s best hutchinsonites. Sadly for mineral collectors, little mining is done here now, but some ramp work and development work have led to occasional interesting finds.

The next (deep yellow) zone, the Transition Zone, includes predominant sphalerite, with pyrite, tetrahedite-tennantite, chalcopyrite, galena, marcasite, arsenopyrite, covellite, seligmannite, jamesonite, quartz, calcite and rhodochrosite. Company records also indicate alabandite has been found in this zone.

The third (light yellow),the Lead-Zinc Zone, has been an area of high mining activity in recent times, in part due to the silver content. Mineralization includes galena, sphalerite, pyrite, chalcopyrite, tetrahedrite-tennantite, marcasite, jamesonite and arsenopyrite. Crowley, Currier and Szenics (1997) report gratonite and wurtzite from the Lead-Zinc Zone. Other minerals from this zone include quartz, calcite, dolomite and rhodochrosite. The company reports clinozoizite and manganaxinite from this zone.

Finally the outer (beige) zone is the Stibnite Zone, which is mostly beyond the area of the Quiruvilca Mine workings. Minerals of the Stibnite Zone include stibnite, arsenopyrite, arsenic, pyrite, chalcopyrite, sphalerite and galena.

Vein mineralization and paragenesis are discussed well in Crowley, Currier and Szenics (1997).

Quiruvilca Minerals 

We did our best to procure minerals from Quiruvilca! Underground work did not result in anything spectacular, although on the day I was grounded with altitude sickness Dave found some pretty great seligmannites. These are microscopic crystals only, but they have great form and iridescent colour:

Selig3Seligmannite. Field of view 1mm. (D.K. Joyce specimen and photo.)

Selig2Seligmannite. Field of view 1mm. (D.K. Joyce specimen and photo.)

Selig1Seligmannite on sphalerite. Field of view 1mm. (D.K. Joyce specimen and photo.)

We tried to buy in Quiruvilca, but specimens were incredibly scarce. We knocked on doors at miners’ homes…

Town3

Town2

…mostly to no avail, but we came up with a few things…

Pyrite1

…including a beautiful pyrite with octahedral crystal forms, totally overgrown by a second generation of pyritohedral crystals.  8cm across.

Most specimens make their way out of town within a short time of extraction from the mine – usually with runners who transport them ultimately to the mineral dealers in Lima. From there, many specimens go on to international mineral shows. One’s chances of intercepting fine mineral specimens at Quiruvilca itself are very low!

In any event, here are a few additional mineral specimens from Quiruvilca:

Arsenic

Arsenic – 10 cm

QuiruvilcaEnargite

Enargite with pyrite – a great specimen from earlier mining days in the Enargite Zone – 8 cm

Bournonite, Quiruvilca, La Libertad, Peru

Bournonite crystals on quartz – 6 cm

QuirvilcaOrpiment(5.5)

Orpiment – 5.5 cm

QuiruvilcaRealgar

 Realgar crystals up to 1 cm on orpiment.

Wavellite

Wavellite balls (to 5 mm) on quartz, from recent mining.

Wavellite2

Wavellite balls to 5 mm

Hutch3Hutchinsonite 8 mm tall with orpiment.  (D.K Joyce specimen and photo.)

QuirvilcaHutchisonite

Hutchinsonite crystals to 6 mm with tiny orpiment crystals.
Field of view approximately 3.8 cm.

Hutch1

Hutchinsonite with barite, orpiment and baumhauerite-2a, field of view 3 cm. (D.K. Joyce specimen and photo.)

Iridescent

Iridescent Sphalerite with micro Seligmannite and Quartz – Field of view 1 cm

Please note – the specimens photographed for this post are not available for sale on this website, but great Peruvian minerals are available here.

From Quiruvilca Along the Rio Moche Valley

We had a lucky break in the weather for our trip through the mountains and along the valley, so I thought I would end this post with some scenes from along the way.

Mountain1

Andes Mountains, from near Quiruvilca

Mtn2Rural dwellings, near Quiruvilca

Mtn3

Upper Rio Moche Valley (some limited farming along the valley)

Mtn4

Rio Moche Valley

Mtn5

Farms further down the valley

Farm1

Picturesque small farm

Otuzco

Veranda in Otuzco  (Might not hold party on this one)

Mtn6

Back to paved highway (thankfully!). Note traffic racing down middle of road.

Mtn8

Andes Mountains

Mtn7

Andes Mountains, with the clouds just beginning to move in

Thanks

First, of course, this could never have happened without an amazing effort organized by Adolfo and his team at Southern Peaks Mining. Thank you Adolfo! Thanks also to Pio, Edgar, Jose and Mauro for great geological, mineralogical, historical and technical insights. Thanks to Wilder, not only for all the driving around us Quiruvilca, but for dodging all those potholes on the road to and from Trujillo – and thanks to Marina for all the great meals. Special major thanks to Miguel and Mr. Oxygen Tank!

References

Excellent references for Quiruvilca and other Peruvian localities:

Crowley J.A., Currier, R.H. and Szenics T. (1997) Mines and Minerals of Peru.  The Mineralogical Record. July-August, 1997, vol 28, no. 4.

Hyrsl, J, Crowley J.A., Currier, R.H. and Szenics T. (2010) Peru – Paradise of Minerals. Soregaroli, A. and Del Castillo, G., eds.

Hyrsl, J and Rosales, Z. (2003) “Peruvian Minerals: An Update” The Mineralogical Record. May-June 2003, vol 34, no.3.

Southern Peaks Mining website: www.southernpeaksmining.com