Color
Brown, White, Greenish, gray, Green, Brownish
Black
Chemical Composition
(Mg,Fe2+ ) 2(Mg,Fe2+ ) 5Si 8O 22(OH) 2Anthony et al , Handbook of mineralogy (2001)
Celestite, Andalusite, Feldspar, Dolomite, Gypsum, Halloysite, Kaolinite, Montmorillonite, Sepiolite, Smectite, Vermiculite