Uneven
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
K(Al,Cr) 3Si 3O 10(OH) 2Gemdat.org , Management Team (2012)
CaB 2(SiO 4) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references