Conchoidal, Conchoidal, Gemstones of the world (2001)
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
SrCO 3Walter Schumann , Gemstones of the world (2001) More from other references