Variscite

Variscite is a phosphate gem material that forms very much in the same manner as turquoise. It is formed when water percolates down through rocks that contain a lot of phosphate minerals, then encounters rocks rich in aluminum. When the mixture is complete and fills in fissures in the existing rock the end result is nodules of the green color variscite as seen above. While the formation of variscite is reported to be very close to turquoise in method, the coloring elements that result in the green color are significantly different. According to the US Geological Survey and other resources, variscite gets its green color from replacement of some of the aluminum with chromium and iron, which would explain the deeper green color than the green turquoise found in places like Carico Lake, Nevada.

Refractive Index: 1.55 - 1.59
Crystal System: Orthorhombic B-
Specific Gravity: 2.4 - 2.6 range
Hardness: 5
Absorption at 688nm with weaker at 650nm

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