Richterite
Species
Rare · Na(NaCa)Mg₅Si₈O₂₂(OH)₂
A sodium calcium amphibole of metamorphosed limestones, manganese deposits such as Långban and some alkaline igneous rocks and carbonatites. Usually brown, yellow or red-brown, more rarely green or greyish blue.
Identity
- Formula
- Na(NaCa)Mg₅Si₈O₂₂(OH)₂
- Chemical class
- Silicate
- Mineral group
- Actinolite, Hornblende, Nephrite, Tremolite
Crystallography
- Crystal system
- Monoclinic
- Habits
- Prismatic, Fibrous, Bladed
- Fracture
- Uneven
Physical properties
- Mohs hardness
- 6
- Density
- 3.09 g/cm³
- Luster
- Vitreous
- Colors
- blue, brown, brown red, gray violet, yellow
- Streak
- white
- Transparency
- Transparent, Translucent
Geology
- Origins
- Metamorphic, Igneous
- Host rocks
- Marble
- Associated minerals
- Calcite, Diopside, Mica, Olivine
- Found in
- Skarn
- Geography
- Sweden, USA, India
Classification
- Rarity
- Rare
- Gem quality
- No
Sources
- M. Pasero and others, IMA Commission on New Minerals, Nomenclature and Classification, The New IMA List of Minerals, updated September 2026. International Mineralogical Association (CNMNC), 2026.
- Richterite. Mindat.org (Hudson Institute of Mineralogy).
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Richterite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
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