gemstone

Blue opal heart cabochon

Common opal, hydrated amorphous silica (SiO₂·nH₂O), likely blue-dyed or synthetic opalite

AI-generated identification · may be incorrect

Mohs hardness 5.5–6.5; translucent milky blue with a waxy-to-vitreous luster and no cleavage. Opal is amorphous rather than crystalline, with specific gravity about 1.98–2.25; the perfectly uniform color and heart cut suggest treatment or imitation.

Identified August 16, 2026More gemstone →

Explore Blue opal heart cabochon in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Natural opal forms when silica-rich groundwater fills cavities and fractures, commonly in volcanic rocks, over relatively young geological timescales. Blue opal occurs notably in Peru, while commercial blue opalite is man-made glass.

Uses & applications

Used as a cabochon in jewelry, ornamental carvings, and collections; opalite is an inexpensive decorative substitute. It is not generally used in construction.

Geological facts

Unlike precious opal, this specimen shows no obvious play-of-color, suggesting common opal, treated material, or opalite. Opal can lose water and craze with intense heat, dryness, or sudden temperature changes.

Field identification & locations

Field clues include low density, waxy luster, rounded fracture, and lack of visible crystal faces; glass imitation may show bubbles and uniform color. Common sources include Australia, Ethiopia, Mexico, Peru, and Nevada.