gemstone

Blue gemstone, likely tumbled sapphire or blue spinel

Corundum (Al₂O₃) if sapphire; alternatively spinel (MgAl₂O₄)

AI-generated identification · may be incorrect

Small polished blue translucent specimen with vitreous luster; sapphire hardness Mohs 9, spinel 8, specific gravity about 4.0 or 3.6, respectively. The image is insufficient to determine crystal structure or cleavage confidently.

Identified August 27, 2026More gemstone →

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At a glance

Common name: Blue gemstone, likely tumbled sapphire or blue spinel
Scientific name: Corundum (Al₂O₃) if sapphire; alternatively spinel (MgAl₂O₄)
Category: gemstone
Identified: August 27, 2026
Method: Standard

AI Estimated Value

Approximately $5–$50 as a tiny common tumbled stone; fine natural faceted sapphire or spinel can range from $100 to thousands of dollars per carat.

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

Blue sapphire forms in aluminum-rich metamorphic rocks or igneous deposits, while blue spinel forms in metamorphosed carbonate rocks; both are geologically ancient and commonly concentrated in alluvial gravels.

Uses & applications

Used primarily as a gemstone in jewelry and as a collector specimen; corundum also has major industrial abrasive applications.

Geological facts

Blue color commonly comes from iron and titanium in sapphire or iron/cobalt in spinel. A refractive-index, hardness, or laboratory gem test is needed for reliable identification.

Field identification & locations

Common sources include Sri Lanka, Myanmar, Madagascar, Tanzania, and Vietnam. Check for natural inclusions, test streak and hardness only cautiously, and distinguish from blue glass or synthetic material.