sedimentary

Jasper

Silicon Dioxide (SiO2) with impurities

Hardness: 6.5-7 Mohs; Color: Red, brown, yellow, green; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Red, brown, yellow, green
Luster: Vitreous to dull

Identified June 21, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Red, brown, yellow, green; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Formation & geological history

Formed from the deposition of silica-rich sediments or volcanic ash. The red and yellow colors are caused by iron oxides (hematite and goethite) that permeate the silica during or after formation. Most jasper is billions of years old, often associated with Precambrian formations.

Uses & applications

Commonly used in jewelry as cabochons or beads, ornamental decor, and historically used for making scrapers or arrowheads due to its conchoidal fracture. It is a popular stone for lapidary work and rock tumbling.

Geological facts

Jasper is a variety of chalcedony. The name comes from the Greek word 'iaspis', meaning 'spotted stone'. It was one of the favorite gemstones of the ancient world, frequently mentioned in biblical texts and used in the breastplates of high priests.

Field identification & locations

Identify in the field by its opaque nature (even on thin edges), its hardness (can scratch glass), and its distinctive earthy colors and smooth, waxy feel when water-worn. Common in riverbeds and glacial deposits.