Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Metallic
Uneven, Uneven, Gemstones of the world (2001) More from other references
PbCa 3Zn 4(SiO 4) 4Anthony et al , Handbook of mineralogy (2001)
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references