mineral

Polished red-and-black jasper

Jasper, microcrystalline quartz (SiO₂), colored by iron oxides and other inclusions

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque, reddish-brown to black mottling, glassy to waxy luster, cryptocrystalline quartz with no visible cleavage; specific gravity approximately 2.5–2.7.

Identified August 30, 2026More mineral →

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Physical properties

Hardness about 6.5–7 Mohs; opaque, reddish-brown to black mottling, glassy to waxy luster, cryptocrystalline quartz with no visible cleavage; specific gravity approximately 2.5–2.7.

Formation & geological history

Forms when silica-rich fluids replace or cement fine-grained sediments or volcanic material, with iron producing the red-brown colors. Most jasper is Paleozoic to younger, though its exact age depends on locality.

Uses & applications

Used for tumbled stones, cabochons, carvings, beads, and decorative objects; occasionally used as an ornamental stone in small architectural pieces.

Geological facts

The specimen appears polished and likely represents brecciated or orbicular-style jasper rather than a distinct mineral crystal. Its patterns arise from iron-rich fluids, impurities, and silica replacement.

Field identification & locations

Identify by its opaque coloration, high polish, lack of cleavage, and resistance to scratching by steel; quartz-rich jasper should not fizz in dilute acid. Common sources include India, Madagascar, Brazil, Australia, Mexico, and the western United States.