sedimentary

Jasper (Iron-stained Quartzite/Chert)

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) impurities

Hardness: 6.5-7 on the Mohs scale; Color: Reddish-orange to brown due to iron content; Luster: Dull to waxy; Crystal Structure: Microcrystalline (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.5–2.9

Hardness: 6
Color: Reddish-orange to brown due to iron content
Luster: Dull to waxy

Identified March 24, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the deposition of silica-rich fluids in volcanic or sedimentary environments, often associated with iron-rich hydrothermal activity. This specimen shows signs of being water-worn or weathered, common in fluvial (river) deposits.

Uses & applications

Used primarily for lapidary work, jewelry (cabochons, beads), and as an ornamental stone. In ancient times, it was used for making tools and seals.

Geological facts

Jasper has been used as a gemstone for thousands of years; it was mentioned in the Bible and used in the Minoan palace of Knossos. The red color specifically comes from the oxidation of iron, essentially 'rust' trapped within the silica matrix.

Field identification & locations

Identify by its hardness (it will scratch glass) and its opaque, waxy appearance. Commonly found in riverbeds, glacial tills, and desert pavements worldwide. Collectors look for unique patterns or deep saturation of color.

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