Uneven, UnevenAnthony et al, Handbook of mineralogy (2001)
ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
Pb 5Cu 2(SO 4) 3(CO 3)(OH) 6Anthony et al , Handbook of mineralogy (2001)
SiO 2(+Al 2O 3)Walter Schumann , Gemstones of the world (2001)