sedimentary

Jasper

Silicon Dioxide (SiO2) with impurities

Hardness: 6.5-7 (Mohs scale); Color: Red, brown, and pinkish bands; Luster: Vitreous to waxy; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

Hardness: 6
Color: Red, brown, and pinkish bands
Luster: Vitreous to waxy

Identified June 28, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica-rich fluids in volcanic ash or sedimentary environments. The coloration comes from mineral inclusions like iron oxides, deposited over millions of years primarily during the Mesozoic eras.

Uses & applications

Used extensively in jewelry as cabochons, for ornamental carvings, seal stones, and as a popular decorative gemstone for collectors due to its unique patterns.

Geological facts

Jasper is an opaque variety of chalcedony. The name stems from the Greek 'iaspis', meaning spotted stone. It has been used for millennia; ancient Egyptians used it for amulets, and it is mentioned in the Bible as one of the stones in the High Priest's breastplate.

Field identification & locations

Identify in the field by its waxy luster, opacity, and hardness (it will scratch glass). Commonly found in river beds, beaches, or volcanic regions in locations like Oregon (USA), Brazil, and India.