Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Metallic
SiO 2 · nH 2OGemdat.org , Management Team (2012)
PbCa 3Zn 4(SiO 4) 4Anthony et al , Handbook of mineralogy (2001)