Scapolite
Scapolite group
Uncommon · (Na,Ca)₄(Al,Si)₁₂O₂₄(Cl,CO₃,SO₄)
A group of sodium calcium aluminium silicates of metamorphic marbles, calcareous gneisses and skarns, running from sodium-rich marialite to calcium-rich meionite. It often fluoresces orange to yellow, some stones show a cat's eye, and it commonly replaces plagioclase in altered rocks.
Identity
- Formula
- (Na,Ca)₄(Al,Si)₁₂O₂₄(Cl,CO₃,SO₄)
- Chemical class
- Silicate
- Members
- Marialite, Meionite
- Also known as
- Wernerite, Meionite (calcium-rich end), Marialite (sodium-rich end)
Crystallography
- Crystal system
- Tetragonal
- Habits
- Prismatic, Massive
- Fracture
- uneven to conchoidal
Physical properties
- Mohs hardness
- 6
- Density
- 2.65 g/cm³
- Luster
- Vitreous
- Colors
- yellow, orange, pink, purple, colorless, gray
- Streak
- white
- Transparency
- Transparent, Translucent
Geology
- Origins
- Metamorphic
- Host rocks
- Schist and gneiss, Marble
- Associated minerals
- Calcite, Diopside, Garnet, feldspar
- Found in
- Skarn
- Geography
- Tanzania, Myanmar, Canada, Brazil, Madagascar
Classification
- Rarity
- Uncommon
- Gem quality
- Yes
Sources
- Scapolite. Mindat.org (Hudson Institute of Mineralogy).
- 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, Marialite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Meionite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
Browse the Crystal Encyclopedia — MGS Toolbox