gemstone

Blue opalite (often sold as synthetic opal)

Opalite glass; amorphous hydrated silica if natural opal (SiO₂·nH₂O)

AI-generated identification · may be incorrect

The specimen is a smooth, translucent blue-green cabochon with milky adularescent-like glow and polished luster. Synthetic opalite glass has no Mohs hardness classification as a mineral (about 5–6), no cleavage, and an amorphous structure; natural opal is Mohs 5–6.5.

Identified August 11, 2026More gemstone →

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Physical properties

Formation & geological history

The pictured material most likely is human-made opalite glass, produced by melting and cooling silica-based glass; it has no geological age. Natural common opal forms when silica-rich groundwater deposits hydrated silica in cavities and fractures, commonly in volcanic rocks.

Uses & applications

Used for inexpensive cabochons, beads, carvings, and decorative objects. Typical value is about $2–$15 for a small polished piece; exceptional natural opal would be substantially more valuable.

Geological facts

Opalite’s blue glow is an optical effect from light scattering and reflection, not true opal play-of-color. It is commonly mislabeled as “sea opal” or “moonstone opal.”

Field identification & locations

Uniform color, rounded bubbles, glassy translucence, and lack of natural patterning suggest synthetic opalite; a loupe may reveal bubbles. Common sources include China and India; natural opal occurs widely in Australia, Ethiopia, Mexico, and the western United States.