aragonite - "cave calcite" - El Potosi Mine, Santa Eulalia Mining District, Chihuahua - hand/display specimen leading to the formation of

leading to the formation of lens-shaped orebodies of magnesite

These bottles are 250 ml

In the field photo

incomplete

iridescent angular basalt sand from the top of a lava flow at Kalapana

aragonite - "cave calcite" - El Potosi Mine, Santa Eulalia Mining District, Chihuahua - hand/display specimen leading to the formation ofaragonite 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