Uneven, Uneven, Gemstones of the world (2001) More from other references
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
Ca 10Mg 2Al 4(SiO 4) 5(Si 2O 7) 2(OH) 4Ulrich Henn and Claudio C.
K(Ca,Na) 2Si 4O 10(OH,F) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references