mineraloid
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Hardness: 5.5 to 6 on the Mohs scale. Color: Pastel pink, often with white, cream, or black dendritic inclusions. Luster: Vitreous to waxy. Crystal Structure: Amorphous (non-crystalline). Cleavage: None (conchoidal fracture). Specific Gravity: 1.9 to 2.3.
- Hardness
- 5
- Luster
- Vitreous to waxy
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Physical properties
Hardness: 5.5 to 6 on the Mohs scale. Color: Pastel pink, often with white, cream, or black dendritic inclusions. Luster: Vitreous to waxy. Crystal Structure: Amorphous (non-crystalline). Cleavage: None (conchoidal fracture). Specific Gravity: 1.9 to 2.3.
Formation & geological history
Formed at low temperatures from silica-rich waters that seep into fissures and cavities in volcanic or sedimentary rock. Pink Peruvian opal is notably found in the Andes Mountains within Tertiary-aged volcanic sequences.
Uses & applications
Primarily used as a gemstone for jewelry (cabochons, beads), decorative carvings, and in metaphysical/healing stone collections.
Geological facts
Unlike 'precious' opal, pink opal is a 'common' opal, meaning it lacks play-of-color. Its pink hue is often attributed to small amounts of organic compounds known as quinones or manganese inclusions.
Field identification & locations
Identify in the field by its distinct pastel pink hue, lightweight feel compared to quartz, and waxy texture. Major sources include the Andes Mountains in Peru, Australia, and parts of the United States (Oregon).
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