(Sepiolite)
Chemistry: Hydrated magnesium silicate
Crystal system: Orthorhombic; microcrystalline; an intermediate mixture of a fine fibrous material and an amorphous substance of the same composition.
Color: Opaque.
Hardness: 2 – 2.5
Cleavage: -
Specific gravity: 2; very porous (when dry it will float in water)
Refractive index: 1.53 mean.
Luster: Earthy
Dispersion: -
Dichroism: -
Occurrence: Alluvial deposits; Greece, Spain, USA, Morocco.
Notes
Soft white and very porous, stains readily (can float); meerschaum from the German word meaning ‘sea foam’; sepiolite from the Greek meaning ‘cuttlefish’; alteration product of serpentine and magnesite; fluorescence: bright blue (long wave); carvings, pipes.
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