Rock Identifier
Red jasper / iron-rich chert (Microcrystalline quartz (SiO₂), commonly colored by hematite or goethite) — sedimentary
sedimentary

Red jasper / iron-rich chert

Microcrystalline quartz (SiO₂), commonly colored by hematite or goethite

AI-generated identification · may be incorrect

Opaque brick-red to brown, with gray-white weathered areas and a dull to slightly waxy luster; hardness about 6.5–7, no visible cleavage, conchoidal fracture, and fine cryptocrystalline structure. The rough surface appears partly coated or weathered, so exact identification is uncertain from the image.

Identified More sedimentary
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Physical properties

Opaque brick-red to brown, with gray-white weathered areas and a dull to slightly waxy luster; hardness about 6.5–7, no visible cleavage, conchoidal fracture, and fine cryptocrystalline structure. The rough surface appears partly coated or weathered, so exact identification is uncertain from the image.

Formation & geological history

Jasper forms when silica-rich fluids replace or cement sediments, often incorporating iron oxides; many deposits are Precambrian to younger. It commonly occurs in volcanic-sedimentary terrains, iron formations, and hydrothermal veins.

Uses & applications

Used as ornamental stone, carvings, cabochons, beads, and lapidary material; historically, jasper was also used for tools and small decorative objects.

Geological facts

The red color is typically caused by dispersed hematite rather than the quartz itself. It may grade into chert, agate, iron formation, or brecciated jasper.

Field identification & locations

Look for opaque red color, very fine texture, hardness sufficient to scratch glass, and conchoidal fracture; a streak test is usually white to pale red. Common sources include India, Brazil, Madagascar, the western United States, and Australia.