Oligoclase identification and geology

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• Albite
• Andesine
• Orthoclase

Sources, scope & corrections

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.

Editorial owner

GeoMiner

Last updated

2026-03-30T14:36:44.236659+00:00

Review status

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.

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Common questions

What is Oligoclase?

Plagioclase feldspar intermediate between albite and andesine. Sunstone is a gem variety with aventurescence.

How can you identify Oligoclase?

Compare several properties rather than relying on colour alone. This entry records colour: White, greenish, reddish; lustre: Vitreous; 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 Oligoclase form?

Crystallizes from intermediate magmas; common in granodiorites and some metamorphic rocks.

Where is Oligoclase commonly found?

Norway sunstone , India, USA; found in granodiorites and gneisses.

What is Oligoclase commonly confused with?

Oligoclase may be confused with Albite, Andesine, Orthoclase. Compare multiple diagnostic properties because colour and surface appearance can overlap.