Kornerupine is a rare borosilicate mineral that is even more rarely found in gem grade. It was first discovered in Greenland in 1884 and is named after the Danish geologist Andreas Nikolaus Kornerup. The color of Kornerupine can range from a dark olive green to a light blue-violet as well orange and nearly colorless. The most desirable colors are the bright greens and blues. It is highly pleochroic and will often show more than one color hue in a finished gemstone.
There are no named varieties or species of Kornerupine. Cats-eye gems have been found.
Where is it found
Kornerupine is found in just a few locations around the world. While it was discovered in Greenland, most gem grade Kornerupine comes from Tanzania, Kenya or Madagascar in Africa, or Sri Lanka and Myanmar in Asia.
There are no known treatments used with Kornerupine.
Use in jewelry
Kornerupine is relatively hard–around 6.5-7.0 on the Mohs scale, and has decent toughness, so its suitable for jewelry. Given its rarity, its mostly bought by gem collectors.
You can look at my current inventory of loose gemstones online here: http://www.earthstreasury.com/product-category/gemstones/collector/kornerupine/