mineral

Iron-rich jasper or brecciated chert

Microcrystalline quartz (SiO₂) with hematite/goethite inclusions

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; reddish-brown, gray, and cream mottling; dull to waxy luster; dense, opaque, cryptocrystalline quartz with conchoidal fracture and no cleavage.

Identified September 13, 2026More mineral →

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Physical properties

Hardness about 6.5–7 Mohs; reddish-brown, gray, and cream mottling; dull to waxy luster; dense, opaque, cryptocrystalline quartz with conchoidal fracture and no cleavage.

Formation & geological history

Forms when silica-rich groundwater cements or replaces sediments, with iron oxides producing the red-brown color; typically Phanerozoic sedimentary deposits, though the exact age is unknown.

Uses & applications

Used for cabochons, beads, carvings, tumbled stones, and small ornamental objects; common pieces have modest collector value.

Geological facts

The red coloration commonly comes from finely dispersed hematite, while yellow-brown areas may contain goethite or limonite. Its irregular pattern could indicate brecciation or weathering.

Field identification & locations

Identify by its very hard, glass-scratching surface, opaque iron-rich coloration, and waxy/conchoidal fracture; common in iron-formation and chert-bearing regions worldwide. A definitive identification requires streak, hardness, and microscopic examination.