Uneven, Uneven, Gemstones of the world (2001) More from other references
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references
Ca 10Mg 2Al 4(SiO 4) 5(Si 2O 7) 2(OH) 4Ulrich Henn and Claudio C.
SiO 2 · nH 2OGemdat.org , Management Team (2012)