Cordierite

Info: Cordierite is a very hard mineral, available in various colour variations. It often grows in the form of pseudo-hexagonal twins. The most valued cordierites are the blue ones. Cordierite grows in masses rich of aluminum with secondary methamorphosis.

How to recognize: Cordierite is hardly dissolved in mineral acids and hardly melts in fire. It can be subjected to erosion and dissolved into a mass of chlorides and various other minerals.

Found: Cordierite was found in Sri Lanka, Barma, Finland, Norway, Sweden and Germany. In Czech Republic two new types of cordierite were found in Dolných borů and Věžné (Morava).

Used for: Mainly in jewelry.