.
Questions and phone orders: 10 AM - 10 PM Pacific (760) 920-6465
1 left

aragonite - "cave calcite" - El Potosi Mine, Santa Eulalia Mining District, Chihuahua - display specimen

$ 50.00

aragonite CaCo3

Aragonite is a pseudomorph of calcite, with the same chemical formula, calcium carbonate, but a different crystal structure. When carbonated groundwater contains calcium, it most commonly precipitates calcite when cold and aragonite, when hot.

Sometimes called "cave calcite," this aragonite comes from the Potosi Mine in the Santa Eulalia Mining District, Chihuahua, Mexico. The silver, lead, zinc and copper ores in this mine are associated with thick-bedded limestones overlain by a series of rhyolite flows and tuffs. In 1912, miners broke into a cavern lined with cave calcite forms similar to these specimens. In subsequent years, numerous cavities have been discovered, with at least some specimens extracted before the cavern was destroyed by mining.

As described in 1925 by mining engineer Carl Millikan, "one cave, the 'Gypsum' cave, when opened, presented a fairyland-like scene. Pure dazzling white, filled with crystals of all shapes and sizes, it was a bonanza for specimens of everything - but ore."

Both sides of this specimen are shown. Tips of this example fluoresce under shortwave ultraviolet.

The pencil is 5.5" long, for scale.




 


Making multiple purchases? Click on the "combine shipping" button in the shopping cart. We'll send an invoice with the correct shipping. A link in that invoice will bring you back to checkout, no hassle.

Shipping: By Priority Mail or USPS Ground Advantage, whichever is cheaper, unless we find a better rate. Click > here < for shipping rates. See comment at Note! Use back button to return to this page.