mineral

Tumbled jasper pebble

Jasper, microcrystalline quartz (SiO₂) with iron-oxide inclusions

AI-generated identification · may be incorrect

Opaque, reddish-purple and cream mottling with a waxy to dull luster; hardness about 6.5–7 Mohs, no visible cleavage, cryptocrystalline quartz structure, and specific gravity around 2.5–2.7.

Identified September 6, 2026More mineral →

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Physical properties

Opaque, reddish-purple and cream mottling with a waxy to dull luster; hardness about 6.5–7 Mohs, no visible cleavage, cryptocrystalline quartz structure, and specific gravity around 2.5–2.7.

Formation & geological history

Jasper forms when silica-rich fluids replace or cement volcanic ash, sediment, or other rock, with iron oxides producing the red coloration. Its exact geological age cannot be determined from the photograph; deposits range from Precambrian to much younger.

Uses & applications

Commonly cut and polished for cabochons, beads, carvings, and decorative objects; also sold as an inexpensive lapidary and collecting material.

Geological facts

The specimen appears tumbled and polished, so its original texture and host rock are obscured. Cream veins or patches may represent quartz, chalcedony, or altered matrix.

Field identification & locations

Identify jasper by its opacity, fine grain, hardness, and red iron-stained patterns; it does not show the translucent crystalline appearance of ordinary amethyst or clear quartz. Similar material occurs worldwide, including India, Madagascar, Brazil, Australia, and the western United States.