gemstone

Polished brecciated jasper

Jasper, an opaque microcrystalline quartz variety (SiO₂), with iron-oxide and clay/mineral inclusions

AI-generated identification · may be incorrect

Typically Mohs 6.5–7; opaque, cream, tan, greenish, brown, and reddish mottling with a waxy to vitreous polish. Quartz is cryptocrystalline, with no visible cleavage; specific gravity is about 2.5–2.7.

Identified August 12, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater replaces or cements volcanic ash, sediment, or fractured rock, producing brecciation and iron staining. Deposits are generally Phanerozoic, with exact age dependent on locality.

Uses & applications

Used for cabochons, worry stones, carvings, beads, bookends, and decorative objects; durability also suits small ornamental stonework. Common polished pieces usually sell for about $10–$40, with exceptional patterns or large specimens reaching $50–$150.

Geological facts

The angular cream, brown, and reddish fragments in a finer matrix indicate brecciated jasper rather than uniform chalcedony. Red and brown colors commonly result from hematite or goethite.

Field identification & locations

Commonly found in volcanic and hydrothermal terrains, including Oregon, Idaho, Utah, California, Madagascar, Brazil, and Australia. Identify it by its opaque silica-rich body, hardness, lack of cleavage, and resistance to scratching by a steel knife; a locality-specific name requires provenance.