sedimentary

Iron-stained brecciated chert or jasper

Microcrystalline quartz (SiO₂), likely chert/jasper with iron-oxide staining

AI-generated identification · may be incorrect

Typically hardness 6.5–7, dull to waxy or slightly vitreous luster, opaque, and brown, gray, black, and reddish-orange. The angular mottling suggests brecciation, with quartz microcrystals and possible hematite/goethite coatings; cleavage is absent and specific gravity is about 2.6.

Identified August 13, 2026More sedimentary →

Explore Iron-stained brecciated chert or 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

Formed when silica-rich sediment or replacement material lithified, fractured, and was recemented; iron-bearing fluids produced the orange-brown staining. Its precise age cannot be determined from the photograph and depends on the host formation.

Uses & applications

Used as decorative stone, lapidary material, cabochons, beads, and occasionally aggregate; attractive pieces may be polished or tumbled.

Geological facts

Chert and jasper are varieties of cryptocrystalline quartz, so individual crystals are generally invisible without magnification. Brecciated varieties can resemble meteorites but usually lack a fusion crust and metallic grains.

Field identification & locations

Look for a very hard surface that scratches glass, a conchoidal fracture, no cleavage, and a fine-grained texture; a streak test may leave little or no mark, unlike softer iron oxides. Common in sedimentary basins and hydrothermal replacement zones worldwide.