High-pressure calcium aluminum silicate characteristic of blueschist-facies metamorphism in subduction zones. Color: Colorless, pale blue, gray. Luster: Vitreous to greasy. Streak: White. Cleavage: Perfect in two directions. Hardness: 8. Transparency: Translucent. Crystal system: Orthorhombic. Chemical formula: CaAl₂Si₂O₇ OH ₂·H₂O. Specific gravity: 3.09. Formation: Forms under high-pressure, low-temperature conditions in subduction zone metamorphism alongside glaucophane. Common geological settings: California Tiburon Peninsula , New Caledonia, Japan; found in blueschist-facies rocks. Common look-alikes and related entries: Glaucophane, Kyanite, Zoisite.
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These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.
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Last updated
2026-03-30T14:37:50.093072+00:00
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Published; not independently peer-reviewed
IMA–CNMNC List of Mineral Names — International Mineralogical Association. Official mineral-name, nomenclature, and classification records.
Mineral ID Key — Mineralogical Society of America. Physical-property identification methods, repeat-testing guidance, and limitations.
High-pressure calcium aluminum silicate characteristic of blueschist-facies metamorphism in subduction zones.
How can you identify Lawsonite?
Compare several properties rather than relying on colour alone. This entry records colour: Colorless, pale blue, gray; lustre: Vitreous to greasy; streak: White; Mohs hardness: 8; cleavage: Perfect in two directions; crystal system: Orthorhombic; transparency: Translucent. Confirm an important identification with additional field tests or qualified laboratory work.
How does Lawsonite form?
Forms under high-pressure, low-temperature conditions in subduction zone metamorphism alongside glaucophane.
Where is Lawsonite commonly found?
California Tiburon Peninsula , New Caledonia, Japan; found in blueschist-facies rocks.
What is Lawsonite commonly confused with?
Lawsonite may be confused with Glaucophane, Kyanite, Zoisite. Compare multiple diagnostic properties because colour and surface appearance can overlap.
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