Plagioclase feldspar famous for labradorescence — a vivid play of iridescent blue, green, and gold colors from internal lamellae. Color: Gray with blue-green iridescence. Luster: Vitreous to pearly. Streak: White. Cleavage: Perfect in two directions. Hardness: 6-6.5. Transparency: Translucent to opaque. Crystal system: Triclinic. Chemical formula: Ca,Na Al,Si AlSi₂O₈. Specific gravity: 2.69-2.72. Formation: Crystallizes from mafic magmas; iridescence results from exsolution lamellae at submicroscopic scale. Common geological settings: Labrador Canada , Finland, Madagascar, Ukraine; found in gabbros and basalts. Common look-alikes and related entries: Moonstone, Andesine, Bytownite.
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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
2026-03-30T14:36:44.535266+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.
Plagioclase feldspar famous for labradorescence — a vivid play of iridescent blue, green, and gold colors from internal lamellae.
How can you identify Labradorite?
Compare several properties rather than relying on colour alone. This entry records colour: Gray with blue-green iridescence; lustre: Vitreous to pearly; streak: White; Mohs hardness: 6-6.5; cleavage: Perfect in two directions; crystal system: Triclinic; transparency: Translucent to opaque. Confirm an important identification with additional field tests or qualified laboratory work.
How does Labradorite form?
Crystallizes from mafic magmas; iridescence results from exsolution lamellae at submicroscopic scale.
Where is Labradorite commonly found?
Labrador Canada , Finland, Madagascar, Ukraine; found in gabbros and basalts.
What is Labradorite commonly confused with?
Labradorite may be confused with Moonstone, Andesine, Bytownite. Compare multiple diagnostic properties because colour and surface appearance can overlap.
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