Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
111 (perfect in four directions)
{111} Indistinct, {111} Indistinct, {111} Indistinct
C
(K,Cs)Al 4Be 4(B,Be) 12O 28Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references