Toal del Mason, Monzoni Mts, Fassa Valley, Trento Province (Trentino), Trentino-Alto Adige, Italy

Ca₂Mg₅Si₈O₂₂(OH)₂

Crystal System: monoclinic
Colour: white, brown, colourless, grey, light green, green, light yellow or pink-violet
Habitus:  fibrous to granular aggregates. Crystals are prismatic to acicular
Lustre: vitreous, silky in fibrous aggregates
Hardness: 5-6
Cleavage: perfect on {110}
Fracture: splintery
Density: 2.964 g/cm³
Origin and geological occurrence: tremolite occurs in dolomitic marbles, serpentinites and talc-bearing schists

www.mindat.org

Samples:

9D.12 Tremolite Fibrous prismatic crystals in carbonates. Crevoladossola, Verbano-Cusio-Ossola, Piedmont #inosilicates