sedimentary

Red jasper

Microcrystalline quartz (chalcedony), SiO₂, colored mainly by iron oxides

AI-generated identification · may be incorrect

Opaque brick-red to reddish-brown, earthy to dull/waxy luster, massive with no visible crystals or cleavage; Mohs hardness about 6.5–7, specific gravity roughly 2.55–2.70. The sharp conchoidal-looking fracture and contrasting pale vein suggest silica-rich jasper with a healed fracture or brecciation.

Identified September 6, 2026More sedimentary →

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Physical properties

Formation & geological history

Jasper forms when silica-rich groundwater replaces or cements sediment, volcanic ash, or breccia; iron oxides produce the red color. Its precise age cannot be determined from the image and depends on the deposit.

Uses & applications

Used for cabochons, carvings, beads, tumbling, ornaments, and decorative stone; occasionally as aggregate or architectural facing.

Geological facts

Jasper is a variety of opaque chalcedony and may grade into brecciated jasper, chert, or iron-rich silicified rock. Color patterns are often the main source of collector appeal.

Field identification & locations

Identify it by its red opaque color, very hard glassy fracture, lack of cleavage, and inability to scratch with a steel knife; quartz or feldspar grains in the cavity may indicate brecciation. Common sources include India, Madagascar, Brazil, Australia, South Africa, and the western United States.