igneous
Tumbled leopard-skin jasper (probable)
Orbicular rhyolite/jasper; primarily microcrystalline quartz (SiO₂) with feldspar and iron-oxide inclusions
AI-generated identification · may be incorrectHardness about 6.5–7 Mohs; opaque, brown-gray with black orbicular spots and a polished vitreous-to-waxy luster. The rounded shape is human-tumbled; crystal grains are too fine to see, with no obvious cleavage.
Identified More igneous →
Explore Tumbled leopard-skin jasper (probable) 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; opaque, brown-gray with black orbicular spots and a polished vitreous-to-waxy luster. The rounded shape is human-tumbled; crystal grains are too fine to see, with no obvious cleavage.
Formation & geological history
Likely silica-rich volcanic rock whose flow textures or altered cavities produced dark orbicules, later silicified and colored by iron/manganese oxides. Such material is generally Cenozoic to older volcanic rock, depending on locality.
Uses & applications
Used for cabochons, beads, carvings, and decorative polished stones; modest value as a common lapidary material.
Geological facts
“Leopard jasper” is a trade name applied to several spotted jasper or orbicular rhyolite varieties, not one strictly defined mineral species.
Field identification & locations
Identify by its opaque body, rounded dark spots, fine texture, and lack of visible quartz crystals; glassy uniformity or bubbles would suggest imitation. Common sources include Mexico, Madagascar, Australia, and the western United States.
