mineral

Pink Opal

Hydrated silica (SiO2 "n H2O)

Hardness: 5.5-6 on Mohs scale; Color: Pale pink to rose; Luster: Vitreous to waxy; Crystal structure: Amorphous; Cleavage: None (conchoidal fracture); Specific gravity: 1.9-2.3

Hardness: 5
Color: Pale pink to rose
Luster: Vitreous to waxy

Identified June 10, 2026More mineral →

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Physical properties

Hardness: 5.5-6 on Mohs scale; Color: Pale pink to rose; Luster: Vitreous to waxy; Crystal structure: Amorphous; Cleavage: None (conchoidal fracture); Specific gravity: 1.9-2.3

Formation & geological history

Formed at low temperatures from silica-rich groundwater filling cavities in volcanic or sedimentary rocks. It is most notably associated with secondary mineralization in Tertiary and Quaternary volcanic deposits.

Uses & applications

Primarily used as a gemstone for jewelry (cabochons, beads) and as a decorative stone in lapidary arts.

Geological facts

Unlike precious opal, pink opal is a 'common opal' that does not show a play-of-color. Its pink hue is often caused by micro-inclusions of palygorskite or organic compounds.

Field identification & locations

Identify in the field by its waxy luster, lack of fire/play-of-color, pink color, and relative lightness compared to quartz. Common locations include Peru, Australia, and Mexico.