Sillimanite (Rare Cat's Eye Gem)

Item Description

The mineral Sillimanite is trimorphous with the species Kyanite and Andalusite meaning they have the same chemistry, but different crystal habits. The same can be said about Brookite, Anatase and Rutile. Sillimanite is actually pretty rare in gem form, and this stone is one of the few I've seen in this color. This stone has a very distinct "eye" and a really unusual "smoky" silvery color. The stone has pretty good clarity when backlit. We photographed it with a strong light to better show the "eye", so it might not be as distinct depending on what lighting in which you're viewing the stone. Sillimanite is sometimes called "Fibrolite" because of the fibrous nature of the material.