gemstone

Faceted black gemstone, likely black spinel

Spinel (MgAl₂O₄); identification from the image is uncertain

AI-generated identification · may be incorrect

Opaque to near-opaque black, strongly reflective, and faceted into a square cut; spinel has Mohs hardness 8 and a cubic crystal structure, with no cleavage. Similar-looking stones include black diamond, sapphire, and synthetic materials.

Identified October 11, 2026More gemstone →

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At a glance

Common name: Faceted black gemstone, likely black spinel
Scientific name: Spinel (MgAl₂O₄); identification from the image is uncertain
Category: gemstone
Identified: October 11, 2026
Method: Standard

AI Estimated Value

Approximately $5–$100 for a small faceted black spinel, depending on whether it is natural, its quality, and treatment; confirm identity before valuation.

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

Natural spinel crystallizes in igneous and metamorphic rocks and occurs in alluvial deposits; spinel formed over geological time. The cut stone’s specific natural or synthetic origin cannot be determined visually.

Uses & applications

Used in jewelry and gemstone collecting; black spinel is sometimes sold as an affordable alternative to black diamond.

Geological facts

Spinel is a distinct mineral, not a type of sapphire, and occurs in many colors as well as black.

Field identification & locations

A gemological test is needed for reliable identification; check refractive index, density, and inclusions rather than relying on color or cut. Natural black spinel is found in sources including Sri Lanka, Myanmar, and Vietnam.