mineral

Polished brecciated jasper

Brecciated jasper, primarily microcrystalline quartz (SiO₂) with iron-oxide staining and contrasting silica-rich fragments

AI-generated identification · may be incorrect

Typically Mohs 6.5–7; opaque, dark red-brown, cream, gray, and black; vitreous to waxy luster; cryptocrystalline quartz with no visible cleavage and conchoidal fracture. The specimen appears tumbled or polished, with angular color fragments and vein-like pale silica.

Identified August 15, 2026More mineral →

Explore Polished brecciated jasper in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Forms when earlier jasper or chert is fractured, then cemented by silica and iron-rich fluids, commonly in volcanic or hydrothermal environments. Its exact geological age cannot be determined from the photograph; jasper deposits range from Precambrian to Cenozoic.

Uses & applications

Used for cabochons, beads, carvings, polished stones, and decorative objects; occasionally used as ornamental stone. It has little industrial value compared with ordinary quartz aggregates.

Geological facts

The irregular angular pattern distinguishes brecciated jasper from banded agate. Red coloration generally comes from hematite or other iron oxides.

Field identification & locations

Identify by its opaque appearance, hardness, resistance to scratching by steel, and fine-grained texture; it should not show individual quartz crystals. Common sources include India, Madagascar, Brazil, Indonesia, and the western United States.