mineral

Red jasper (likely iron-rich chert)

Jasper; microcrystalline quartz (SiO₂) colored mainly by hematite/goethite

AI-generated identification · may be incorrect

Opaque reddish-brown, earthy to dull/waxy luster, cryptocrystalline quartz with no visible cleavage; Mohs hardness about 6.5–7 and specific gravity roughly 2.5–2.7. The glossy surface appears wet or naturally polished, and dark areas may contain iron oxides or other inclusions.

Identified September 11, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids replace or cement fine sediment, commonly with iron-oxide impurities; deposits range from Precambrian to recent. The specimen may be naturally water-worn or tumbled, so its exact locality and age cannot be determined from the image.

Uses & applications

Used for cabochons, beads, carvings, ornaments, and lapidary pieces; massive jasper is also used decoratively in tiles and architectural stone.

Geological facts

Its red color is typically produced by hematite, while yellow-brown shades reflect hydrated iron oxides. Jasper is a variety of chert distinguished by its opacity and abundant impurities.

Field identification & locations

Identify it by its opaque red-brown color, very fine texture, lack of cleavage, and ability to scratch ordinary glass; a streak test is usually pale reddish-brown. Common sources include India, Madagascar, Brazil, Australia, South Africa, and the western United States.