gemstone

Blue cabochon ring stone, likely sapphire or synthetic blue corundum

Corundum (Al₂O₃), possibly chromium/iron-titanium-bearing sapphire

AI-generated identification · may be incorrect

The stone appears as a deep blue, polished cabochon with vitreous luster in a metal setting; visual identification is uncertain. Natural corundum has Mohs hardness 9, trigonal crystal structure, no cleavage, and specific gravity about 4.0; the surrounding ring is likely metal with clear accent stones.

Identified August 27, 2026More gemstone →

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At a glance

Common name: Blue cabochon ring stone, likely sapphire or synthetic blue corundum
Scientific name: Corundum (Al₂O₃), possibly chromium/iron-titanium-bearing sapphire
Category: gemstone
Identified: August 27, 2026
Method: Standard

AI Estimated Value

Approximately $10–$100 if synthetic or imitation; $100–$2,000+ for a natural sapphire, depending on origin, treatment, color, clarity, and size.

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

Sapphire forms in metamorphic rocks and some igneous deposits, generally over geological timescales; blue color commonly comes from iron and titanium. The image cannot establish whether this is natural, treated, or synthetic.

Uses & applications

Used in jewelry, especially rings; sapphire is highly durable and valuable, while synthetic corundum is comparatively inexpensive.

Geological facts

A cabochon cut often emphasizes color or effects such as asterism rather than brilliance. Reliable identification requires magnification, refractive-index testing, and ideally spectroscopy or a gem laboratory report.

Field identification & locations

Common sources include Sri Lanka, Kashmir, Myanmar, Madagascar, Australia, and Montana. Look for strong blue color, high wear resistance, and possible zoning; do not confuse it with glass, spinel, or blue topaz.