mineral

Oceanside Agate (Orbicular Agate)

Silicon Dioxide (SiO2) - Variety of Chalcedony

Hardness: 6.5-7 (Mohs scale), Color: Greenish-white with circular ring patterns, Luster: Waxy to vitreous, Crystal structure: Trigonal/Microcrystalline, Cleavage: None (conchoidal fracture), Specific Gravity: 2.6-2.7

Hardness: 6

Identified March 31, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica-rich groundwater into cavities in volcanic rocks (often basalt). The orbicular 'eye' patterns result from rhythmic precipitation of silica. These specimens are often millions of years old (CenozoicEra).

Uses & applications

Used primarily by lapidaries as gemstones for cabochons, jewelry, and by mineral collectors for its unique orbicular aesthetic.

Geological facts

Orbicular agates are sometimes referred to as 'Eye Agates' because the circular bands resemble eyes, which were historically believed to ward off the 'evil eye'.

Field identification & locations

Identify by looking for translucent to opaque silica with distinct circular or 'bubbly' banding. Commonly found in coastal areas or volcanic deposits; similar to patterns seen in Ocean Jasper from Madagascar.

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