metamorphic

Likely polished blue-gray stone, possibly labradorite or slate

Tentatively labradorite (plagioclase feldspar, NaAlSi₃O₈–CaAl₂Si₂O₈) or blue-gray slate; identification is limited by the close-up image

AI-generated identification · may be incorrect

Blue-gray, fine-grained to subtly crystalline surface with strong satiny reflections, possibly from polishing or cleavage planes. Labradorite has Mohs hardness 6–6.5 and vitreous luster; slate has hardness about 3–5.5 and dull to silky luster.

Identified September 1, 2026More metamorphic →

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At a glance

Common name: Likely polished blue-gray stone, possibly labradorite or slate
Scientific name: Tentatively labradorite (plagioclase feldspar, NaAlSi₃O₈–CaAl₂Si₂O₈) or blue-gray slate; identification is limited by the close-up image
Category: metamorphic
Identified: September 1, 2026
Method: Standard

AI Estimated Value

Approximately $5–$50 for a common polished piece; attractive, strongly iridescent labradorite specimens may sell for $50–$300+.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Labradorite crystallizes in mafic igneous rocks as molten material cools; slate forms when shale undergoes low-grade metamorphism. Geological ages vary widely depending on source locality.

Uses & applications

Labradorite is used as an ornamental stone, cabochon, and decorative tile; slate is used for roofing, flooring, paving, and architectural surfaces. Value depends strongly on color play, pattern, size, and finish.

Geological facts

The bright blue flashes characteristic of labradorite are caused by light interference within closely stacked feldspar lamellae. Slate commonly shows planar foliation and splits into thin sheets.

Field identification & locations

Check for blue, green, or gold iridescent flashes, feldspar-like hardness, and cleavage to support labradorite; flat foliation and easy splitting favor slate. Common sources include Madagascar, Finland, Canada, Norway, and India.