igneous
Polished leopard-skin jasper (likely orbicular rhyolite)
Orbicular rhyolite, a silica-rich volcanic rock with feldspar and quartz; exact identification from the photo is uncertain
AI-generated identification · may be incorrectPolished, glossy dark brown-black groundmass with cream, red, yellow, and orange rounded spots. Typically fine-grained, with quartz and feldspar (Mohs hardness about 6–7); the visible orbs are mineral-rich volcanic textures, not separate polished inclusions.
Identified More igneous →
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Physical properties
Polished, glossy dark brown-black groundmass with cream, red, yellow, and orange rounded spots. Typically fine-grained, with quartz and feldspar (Mohs hardness about 6–7); the visible orbs are mineral-rich volcanic textures, not separate polished inclusions.
Formation & geological history
Forms when silica-rich lava cools, sometimes developing rounded mineral aggregates during crystallization. Geological age varies by source; similar jasper-like orbicular rocks are collected from several volcanic regions.
Uses & applications
Used for beads, spheres, cabochons, and decorative objects; not generally a major construction stone.
Geological facts
The trade name “leopard-skin jasper” is applied to visually similar materials and does not guarantee a true jasper or a specific locality.
Field identification & locations
Look for naturally varied, rounded spots embedded in a continuous fine-grained matrix. Comparable material is sold from locations including Mexico and South Africa; a sphere’s polish and pattern affect desirability.
