About Riebeckite
A sodium iron amphibole, often dark blue to black. Crocidolite (blue asbestos) is a fibrous variety, which when silicified forms Tiger's Eye. It's associated with insight, problem-solving, and calmness. (Fibrous forms are asbestiform, handle with care).
Primary Hues
Dark Blue, Black, Greenish-Black, (Crocidolite: blue, fibrous)
Geological & Scientific Details
Riebeckite is classified as a silicate mineral mineral which typically crystallizes in the monoclinic system. Its chemical formula is Na2(Fe2+3Fe3+2)Si8O22(OH)2. Common crystal habits include as prismatic crystals, commonly fibrous, asbestiform; earthy, massive.
Key Geological Properties:
- Mineral Category: Silicate mineral
- Chemical Formula: Na2(Fe2+3Fe3+2)Si8O22(OH)2
- IMA Symbol: Rbk[1]
- Crystal System: Monoclinic
- Predominant Geological Color: Black, dark blue; dark blue to yellow-green in thin section
- Crystal Habit: As prismatic crystals, commonly fibrous, asbestiform; earthy, massive
- Twinning: Simple or multiple twinning parallel to {100}
- Cleavage: Perfect on {110}, intersecting at 56° and 124°; partings on {100} and {010}
- Luster: Vitreous to silky
- Streak: Pale to bluish gray
- Diaphaneity: Semitransparent
Associated Minerals
- Amphibole
- Crocidolite
- Tiger's Eye
- Aegirine
- Albite
- Quartz
- Arfvedsonite