Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Granular
(Ca,Na)(Mg,Fe,Al,Ti)(Si,Al) 2O 6Anthony et al , Handbook of mineralogy (2001)
Ca 2(Mg,Fe)Al 2(SiO 4)(Si 2O 7)(OH) 2 · H 2O)Arthur Thomas , Gemstones (2009)