sedimentary
Brecciated jasper
Silicified breccia, chiefly microcrystalline quartz (SiO₂) with iron-oxide pigments
AI-generated identification · may be incorrectHardness about 6.5–7 Mohs; opaque yellow, red, brown, gray, and white angular fragments, commonly with waxy to dull luster and no visible cleavage. Specific gravity is typically 2.5–2.7; the irregular dark seams are likely silica or iron-oxide cement.
Identified More sedimentary →
Explore Brecciated jasper in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness about 6.5–7 Mohs; opaque yellow, red, brown, gray, and white angular fragments, commonly with waxy to dull luster and no visible cleavage. Specific gravity is typically 2.5–2.7; the irregular dark seams are likely silica or iron-oxide cement.
Formation & geological history
Forms when silica-rich fluids or groundwater cement pre-existing rock fragments, often during volcanic or hydrothermal alteration. Its exact age cannot be determined from the photograph and depends on the host formation.
Uses & applications
Used as lapidary rough, cabochons, beads, carvings, and decorative stone; attractive pieces have modest collector value.
Geological facts
The red and yellow coloration is commonly produced by hematite and goethite, while white areas may be quartz or chalcedony. Brecciation gives it angular, mosaic-like patterns rather than the rounded banding of many agates.
Field identification & locations
Identify it by its angular multicolored fragments, very hard silica-rich surfaces, and inability to scratch with a steel knife easily; common sources include volcanic and hydrothermal districts worldwide, especially the western United States, Mexico, Australia, and India.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary