mineral

Tumbled pink opal (likely common opal)

Hydrated amorphous silica, SiO₂·nH₂O; likely pink common opal with manganese/iron inclusions

AI-generated identification · may be incorrect

Usually Mohs hardness 5.5–6.5, waxy to vitreous luster, opaque to translucent, and lacking visible crystal structure or cleavage. The specimen is pale pink with dark dendritic or matrix-like inclusions and a smoothly polished surface.

Identified August 18, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities, fractures, or volcanic pores, with color produced by trace elements and inclusions; opal deposits range from Cenozoic to much older. Exact age and locality cannot be determined from the photograph.

Uses & applications

Used as a lapidary stone for cabochons, beads, carvings, and tumbled specimens; softer varieties are unsuitable for heavy-wear jewelry. It has modest decorative and collector value.

Geological facts

Opal contains structurally bound water and can craze or crack with heat, dehydration, or sudden temperature changes. Common opal lacks the play-of-color characteristic of precious opal.

Field identification & locations

Identify by its low-to-moderate hardness, waxy appearance, smooth conchoidal fractures, and absence of cleavage; avoid prolonged soaking, heat, and ultrasonic cleaning. Similar pink materials include dyed quartz, pink calcite, and ceramic glass, so locality or testing is needed for certainty.