gemstone

Opal pendant

Common precious opal, hydrated amorphous silica (SiO₂·nH₂O), likely treated or assembled

AI-generated identification · may be incorrect

The inset stone shows blue-green play-of-color, vitreous-to-waxy luster, and no true crystal structure. Opal hardness is approximately 5.5–6.5 Mohs, with conchoidal fracture and specific gravity around 1.98–2.25; the metal setting is non-geological.

Identified August 22, 2026More gemstone →

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At a glance

Common name: Opal pendant
Scientific name: Common precious opal, hydrated amorphous silica (SiO₂·nH₂O), likely treated or assembled
Category: gemstone
Identified: August 22, 2026
Method: Standard

AI Estimated Value

Approximately $20–$150 for a commercial assembled or treated opal pendant; $200–$2,000+ for a fine natural opal with documented origin and precious-metal setting.

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

Opal forms when silica-rich groundwater deposits hydrated silica in cavities and fractures, commonly in volcanic or sedimentary rocks. Commercial material is especially associated with Australia, Ethiopia, Mexico, and Nevada; geological ages vary widely.

Uses & applications

Used primarily in jewelry and ornamental objects. The pendant’s value depends on body tone, brightness, color pattern, transparency, treatments, origin, and metal quality.

Geological facts

Precious opal’s colors arise from diffraction by regularly arranged microscopic silica spheres, not pigments. Dark-bodied opal generally displays stronger contrast and is more valuable than pale common opal.

Field identification & locations

Identify it by observing moving spectral flashes under changing light; imitation glass or resin often has overly regular patterns, bubbles, or a higher visual uniformity. Avoid heat, ultrasonic cleaning, harsh chemicals, and prolonged drying.