Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
On {10 1 0}, perfect; parting on {000 1 }
111 (perfect in four directions)
(Zn,Mn2+ )OMichael OâDonoghue , Gems, Sixth Edition (2006)
C