Uneven, Sub-Conchoidal, UnevenWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Metallic
Uneven, Uneven, Gemstones of the world (2001) More from other references
ZnCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Mg,Fe)Al 2(PO 4) 2(OH) 2Arthur Thomas , Gemstones (2009) More from other references