gemstone

Faceted dark gemstone, likely black spinel

Spinel, MgAl₂O₄ (visual identification is uncertain; black sapphire or other dark gems can look similar)

AI-generated identification · may be incorrect

Opaque to near-opaque, black, with a vitreous luster and faceted cut. Spinel has Mohs hardness 8 and a cubic crystal structure; the image alone cannot confirm the material or its properties.

Identified October 11, 2026More gemstone →

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At a glance

Common name: Faceted dark gemstone, likely black spinel
Scientific name: Spinel, MgAl₂O₄ (visual identification is uncertain; black sapphire or other dark gems can look similar)
Category: gemstone
Identified: October 11, 2026
Method: Standard

AI Estimated Value

Approximately $5–$100 for a small commercial dark spinel; value varies substantially with confirmed identity, natural versus synthetic origin, size, and cut.

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

Opaque to near-opaque, black, with a vitreous luster and faceted cut. Spinel has Mohs hardness 8 and a cubic crystal structure; the image alone cannot confirm the material or its properties.

Formation & geological history

Natural spinel forms in metamorphic rocks and some igneous deposits, over a range of geological ages; gem material is also commonly synthetic.

Uses & applications

Used in jewelry, especially as a faceted stone; dark spinel is also collected as a gemstone.

Geological facts

Spinel is often confused with ruby in historical jewelry, though this pictured stone’s identity cannot be established from appearance alone.

Field identification & locations

A gemological test—such as refractive-index measurement or spectroscopy—is needed to distinguish spinel from black sapphire, synthetic material, or other look-alikes. The small, mounted-or-loose cut stone cannot be assigned a locality from the image.