Uneven, Uneven, Gemstones of the world (2001) More from other references
Uneven, UnevenAnthony et al, Handbook of mineralogy (2001)
Ca 10Mg 2Al 4(SiO 4) 5(Si 2O 7) 2(OH) 4Ulrich Henn and Claudio C.
Pb 5Cu 2(SO 4) 3(CO 3)(OH) 6Anthony et al , Handbook of mineralogy (2001)