*from the Blackbird Mine, Lemhi County, Idaho. *75 x 50 x 45 mm overall.
Probably the most recognized location vivianite locations in North America. While this one looks black, you can see in the pictures it still retains its blue-green color toward the ends of the crystals. The size of these crystals plus the color make it a remarkable specimen!
Exposure to light will ultimately darken and it will continue until the specimen is almost black and opaque. This exposure is irreversible and inevitable with any vivianite sample left in the light. There is no such thing as a "stable vivianite".
