Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001)
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal
SiO 2Ulrich Henn and Claudio C.
(Mg,Fe2+ ) 7(SiO 4) 3(F,OH) 2Anthony et al , Handbook of mineralogy (2001)