sedimentary

Polished leopard jasper (likely ocean jasper)

Silicified microcrystalline quartz/chalcedony; mainly SiO₂ with iron-oxide inclusions

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque cream, gray, and reddish-brown orbicular pattern; vitreous to waxy luster when polished; cryptocrystalline, with no visible cleavage. The rounded shape indicates tumbling or natural abrasion.

Identified August 19, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when silica-rich fluids replaced or cemented volcanic ash, breccia, or other rock, while iron oxides produced the red-brown markings. Orbicular ocean jasper is especially associated with Miocene volcanic rocks of Madagascar, though similar jasper occurs worldwide.

Uses & applications

Used for cabochons, beads, carvings, decorative objects, and lapidary specimens; not generally used as a structural stone.

Geological facts

The pattern is caused by concentric silica growth and iron-oxide staining, not necessarily true leopard-like mineral crystals. “Leopard jasper” is a commercial lapidary name applied to several patterned jaspers.

Field identification & locations

Identify it by its opaque chalcedony-like body, waxy polish, red-brown iron staining, and lack of strong cleavage; glassy bubbles or uniform artificial color suggest imitation. Common sources include Madagascar, Mexico, Brazil, and the western United States.