Fluorapatite
Posted by: macadmin on 04.18.2020 | Filed under:

Fluorapatite

Specimen # 100576
Mineral: Fluorapatite
Location: Cerro de Mercado, Victoria de Durango, Durango, Mexico
Size: 6.5 x 5.3 x 4.7 cm
Specimen # 100576
Mineral: Fluorapatite
Location: Cerro de Mercado, Victoria de Durango, Durango, Mexico
Size: 6.5 x 5.3 x 4.7 cm
Price: $125.00 CAD

Quantity:

1 in stock

Description

Detailed Description

A blocky 1.9 cm wide fluorapatite crystal sits on the top of this matrix with tiny sparkling quartz and calcite crystals. The fluorapatite is darker than average, due to some iron inclusions and also because some of the back and left side faces of the crystal are enclosed in quartz-calcite.The result is great contrast with the quartz-calcite surrounding the fluorapatite crystal. It’s hard to capture it quite as dark as it appears, because internally it picks up the light no matter how I illuminate it, but in person it is a bit darker unless you have bright display lights on it. The fluorapatite is lustrous and translucent with some good internal transparency, visible under good light. In excellent condition, minor edge chipping on the back of the termination, as I have shown in the last photo. The contrast and aesthetics are great, and what really makes this one stand out is how sharp and truly glassy it is.

Browse more Cerro de Mercado Fluorapatites (click here)


About These Fluorapatites

 
Crystals of yellow-green fluorapatite from Cerro de Mercado have been known for a long time, and at times they have been produced in abundance. However, truly fine specimens are actually hard to find, as most of the fluorapatites from the mine are badly damaged. In part this is because they have typically been collected in the past without due care (tossed into buckets and so on). But in part it is also due to their own formation history – although their geological origin is still a matter of uncertainty, the crystals always have one termination and one incomplete end (doubly-terminated crystals are not known from Cerro de Mercado) and they are cemented into the matrix, all suggestive of post-crystallization activity within the deposit. This cementing involves varying mineral constituents (some of which are rather unhelpful when it comes to extracting fine mineral specimens). In particular, excellent matrix specimens are very uncommon.

Cerro de Mercado is still a producing iron mine, and the fluorapatite crystals in this lot were collected this year. As contemporary mining and sorting/separation have become mechanized, and also owing to the fact that the apatite at the mine is now concentrated for its phosphate value, the preservation of fine fluorapatite crystals and matrix specimens is a greater challenge than it used to be. Damage is still a rampant problem. I selected the few fine pieces here out of a lot of hundreds of specimens, offered by a seller who lives beside the mine. Although it is likely that specimens will continue to be produced for as long as the mine continues to operate, it is also likely that fine undamaged specimens will continue to be hard to obtain.

The definitive article on this locality is Wendell Wilson’s excellent piece in the Mineralogical Record, Special Issue – Mexico VI, Vol. 42:5, Sept-Oct 2011.


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