Mineral description : Riebeckite

Mineral class Silicates : Inosilicates : Tremolite glaucophan riebeckite group
Chemical formula Na2Fe5Si8O22(OH)2
Crystal system Monoclinic
Cleavage Perfect in two directions.
Hardness 4
Density 3.4
Color Blue, black, dark green, translucent to opaque.
Streak Greenish brown.
Luster Vitreous to silky.
Occurance In magmatic and metamorphic rocks.
Notes Type locality : Socotra island, Indian Ocean, Yemen.
Named after the German traveler, E. Riebeck (1853-1885).
Crocidolite is the name of riebeckite form of asbetos.
  • Norra Kärr, Småland, Sweden.
  • Hörningsholm, Alnön, Sundsvall.
  • Närsta, Alnön, Sundsvall.
  • Skoger, Norway.

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Last changed : 2000-01-01