This sample of almost pure [sillimanite](http://webmineral.com/data/Sillimanite.shtml) is from the Broken Hill district of New South Wales, Australia. Sillimanite is the highest temperature polymorph of the aluminosilicates (Al₂SiO₅), only forming at tenperartures of over 500°. It is often referred to as 'fibrolite', referring to the fibrous habit that forms a prominent lineation in this sample.
Reprocessed model uploaded 13th Feb 2021