Muscovita Fuchsita
Muscovita is a mineral with formula K(Al,Cr)₂(AlSi₃O₁₀)(OH)₂, in the Silicatos (Filosilicatos) group. This specimen comes from MQ Granite AS quarry, Gaskkabeaivári, Kautokeino, Troms og Finnmark, Noruega and joined the Terrium collection in 2025.
Description
Massive green mica plate with strong pearly lustre. Two undulating surfaces, with silvery reflections and white quartz microinclusions visible with a loupe. Dense texture yet exfoliable into flakes like glitter, cool emerald-green colour.
About Muscovita
Fuchsite is a green variety of muscovite in which part of the aluminium is replaced by chromium. It retains the pearly lustre and elasticity typical of micas, unlike chlorites, which are more matt and fragile. It forms in chromium-rich metamorphic rocks, especially schists and quartzites, associated with quartz, kyanite or corundum.
About the locality
Kautokeino forms part of the Karasjok–Kautokeino metamorphic belt in the far north of Norway, one of the oldest regions of the Baltic Shield. Fuchsite in this area develops in chromium-rich schists and quartzites derived from Precambrian ultramafic rocks. Mining activity has long been limited.
Technical data
- Catalogue No.
- 0468
- Internal reference
- T0075
- Composition
- K(Al,Cr)₂(AlSi₃O₁₀)(OH)₂
- Name
- Muscovita
- Variety
- Fuchsita
- Group
- Silicatos (Filosilicatos)
- Associations
- cuarzo
- Mine
- MQ Granite AS quarry
- District / Municipality
- Gaskkabeaivári
- Province
- Kautokeino
- Region
- Troms og Finnmark
- Country
- Noruega
- Size (cm)
- 13 x 9 x 3
- Weight
- 318.2 g
- Acquired
- 2025
- Etymology
- Named after the German mineralogist Johann Nepomuk von Fuchs.
- Quality
- Buena
- Value trend
- Estable