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