Grandidierite
About Grandidierite
One of the rarest gemstones on Earth. Gem-quality material is found primarily in Madagascar. It was named after French explorer Alfred Grandidier. It is strongly pleochroic - showing green, blue, and colorless from different angles. Transparent gem-quality material is extremely rare. Prices can exceed $20,000 per carat for fine stones. Most material is opaque and suitable only for cabochons. It was first described in 1902. Sri Lanka also produces some material. It is a magnesium aluminum borosilicate. Transparent gems over 1 carat are museum-quality specimens.
Related Gemstones
Emerald
Cleopatra mined emeralds in Egypt 4,000 years ago - her mines were lost for centuries. The...
Amethyst
Once as valuable as diamonds until massive deposits were found in Brazil in the 1800s. The...
Topaz
Pure topaz is colorless - the various colors come from impurities or treatments. Imperial ...
Tanzanite
Found in only one place on Earth - a 7 square km area near Mount Kilimanjaro in Tanzania. ...