Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Conchoidal
Uneven, Conchoidal, Brittle
PbCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Ca(Mg 3)MgAl 5(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)