Tanzania, Sri Lanka, China
Australia, Spain, Brazil, Germany, Australia, Spain, Brazil, Germany, Australia, Spain, Brazil
Conchoidal
Conchoidal, Splintery, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle
Gemmological Tables (2004) More from other references
Translucent, Opaque . May be translucent when backlit on the edges.