Gem silica is a bluish green to greenish blue variety of chalcedony that receives its vivid color from the presence of copper. It is often known as "chrysocolla chalcedony" or "gem silica chrysocolla." Chrysocolla being the copper mineral that ranges from turquoise blue to blue-green, and is typically translucent to opaque, with Gem Silica being the silicated version (meaning it is mixed with quartz). It is valued for its bright and consistent turquoise color and high level of translucency.

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