Subconchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Ca 6Si 2(CO 3) 2(SO 4) 2(OH) 12 · 24H 2OUlrich Henn and Claudio C.
BaSO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references