Wollastonite
Species
Common · CaSiO₃
Calcium silicate formed where limestone is baked by an igneous intrusion or altered by silica-bearing fluids. Its needle-like crystals make it a filler and reinforcement in ceramics, paints, plastics and brake linings, and a substitute for asbestos.
Identity
- Formula
- CaSiO₃
- Chemical class
- Silicate
Crystallography
- Crystal system
- Triclinic
- Habits
- Tabular, Massive, Fibrous
- Fracture
- Uneven
Physical properties
- Mohs hardness
- 5
- Density
- 2.9 g/cm³
- Luster
- Vitreous, Silky
- Colors
- white, gray, pale green, colorless
- Streak
- white
- Transparency
- Translucent, Opaque
Geology
- Origins
- Metamorphic
- Host rocks
- Marble, Limestone and chalk
- Associated minerals
- Calcite, Diopside, Grossular, Vesuvianite
- Found in
- Skarn
- Geography
- USA, China, India, Finland, Mexico
Classification
- Rarity
- Common
- 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.
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Wollastonite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- D. W. Olson, Wollastonite, Mineral Commodity Summaries 2026. U.S. Geological Survey, 2026.
- Wollastonite: Mineral information, data and localities. mindat.org.
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