gemstone

Blue-green opal, likely polished common or synthetic opal

Opal (hydrated amorphous silica, SiO₂·nH₂O); identification from the image is uncertain

AI-generated identification · may be incorrect

Translucent pale blue-green body with a glossy polish and possible iridescent play-of-color. Opal has no crystal structure, Mohs hardness about 5.5–6.5, and variable specific gravity around 1.9–2.3; the rounded, shell-like shape may be carved or molded.

Identified October 5, 2026More gemstone →

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At a glance

Common name: Blue-green opal, likely polished common or synthetic opal
Scientific name: Opal (hydrated amorphous silica, SiO₂·nH₂O); identification from the image is uncertain
Category: gemstone
Identified: October 5, 2026
Method: Standard

AI Estimated Value

About $2–$30 if a small common or synthetic piece; natural precious opal can be worth substantially more depending on verified origin, color, and quality.

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 opal forms as silica-rich water deposits gel in rock cavities and later hardens; deposits range from geologically young to Cretaceous age. The pictured piece may instead be synthetic or treated, which cannot be confirmed visually.

Uses & applications

Used in jewelry, carvings, and mineral collections; opal is also used as a decorative gemstone.

Geological facts

Precious opal displays shifting spectral colors from microscopic silica spheres; common opal lacks this effect. The visible blue-green sheen alone does not establish natural origin.

Field identification & locations

Natural opal occurs notably in Australia, Ethiopia, and Mexico. Look for irregular color patches and internal structure under magnification; uniform appearance can suggest synthetic material. Similarity to a shell-shaped object makes confirmation from this image difficult.