![yellow - green sillimanite from Tanzania](https://www.patrickvoillot.com/wp-content/uploads/2021/03/sillimanite-tanzanie67.png)
sillimanite
Discovered in 1824, it honors the name of the American geologist Benjamin Silliman (1779-1864). It is also known for its blue or violet variety called fibrolite. It has been known since prehistoric times and it was used to manufacture cutting tools. There is also a