metamorphic
Leopard-skin jasper (likely orbicular jasper)
Silicified volcanic rock, primarily microcrystalline quartz (SiO₂) with iron-oxide and dark mineral inclusions
AI-generated identification · may be incorrectHardness about 6.5–7 Mohs; cream, tan, brown, and charcoal mottling with a dull to waxy luster. It is dense and non-cleavable, with irregular conchoidal fracture; the exact texture is difficult to confirm from the photograph.
Identified More metamorphic →
Explore Leopard-skin jasper (likely orbicular jasper) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness about 6.5–7 Mohs; cream, tan, brown, and charcoal mottling with a dull to waxy luster. It is dense and non-cleavable, with irregular conchoidal fracture; the exact texture is difficult to confirm from the photograph.
Formation & geological history
Usually formed when silica-rich fluids replace or cement volcanic ash or rhyolitic material, preserving rounded mineral or alteration patterns. Deposits commonly formed in volcanic terrains during the Cenozoic, though age varies by locality.
Uses & applications
Used as a lapidary stone for cabochons, beads, carvings, and tumbled pieces; occasionally used decoratively. This small natural specimen has limited commercial value.
Geological facts
The name refers to its leopard-like spots, not to a biological origin. Similar-looking stones may be rhyolite, porphyry, or ordinary jasper, and laboratory testing may be needed for certainty.
Field identification & locations
Identify by its opaque cream-to-brown body, irregular dark spots, very fine grain, and inability to scratch easily with a steel knife; it should not fizz in dilute acid. Common sources include Mexico, Madagascar, and the western United States.
More like this
