Gems, Conchoidal, Brittle
Conchoidal, Brittle, Metallic, Conchoidal, Handbook of mineralogy (2001)
Ca 3Ti4+2(Fe3+2Si)O 12Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Mg,Fe2+ ) 3Si 2O 5(OH) 4Anthony et al , Handbook of mineralogy (2001)