DESCRIPTION
For a long time this gemstone has only been considered as a collectors stone. Named after Professor Silliman of Yale University. Sillimanite is a rare fusion of Kyanite and Andulusite. It seamlessly blends the pure natural hues of incredibly rare Olive Kyanite and the strong pleochrism found in Andulusite.
When in its noncrystalline form it is known as fibrolite. The name derives from the long slender crystal prisms which resemble fibers. In this form it can have a silky luster and in some cases shows the cats eye effect of chatoyancy.