Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Uneven, Uneven, Gemstones of the world (2001) More from other references
Na 8Al 6Si 6O 24(SO 4) · H 2OAnthony et al , Handbook of Mineralogy (2001)
(Mg,Fe)Al 2(PO 4) 2(OH) 2Arthur Thomas , Gemstones (2009) More from other references