Splintery, Brittle, Uneven
ConchoidalGemdat.org, Management Team (2012), ConchoidalGemdat.org, Management Team (2012)
NaCa 2(Mg 4Al)Si 6Al 2O 22(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006)
(Fe,Mg) 3Al 2(SiO 4) 3gemdat.org , Management Team (2012)