sedimentary

Jasper

Silicon Dioxide (SiO2) with impurities

Hardness: 6.5-7 (Mohs scale), Color: Brown, yellow, and reddish-brown, Luster: Vitreous to dull, Crystal Structure: Trigonal/Microcrystalline, Cleavage: None, Specific Gravity: 2.58-2.91

Hardness: 6

Identified May 24, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs scale), Color: Brown, yellow, and reddish-brown, Luster: Vitreous to dull, Crystal Structure: Trigonal/Microcrystalline, Cleavage: None, Specific Gravity: 2.58-2.91

Formation & geological history

Formed from the deposition of silica from water, often associated with volcanic activity or sedimentary processes. This sample shows typical banding from iron oxidation during formation.

Uses & applications

Used primarily for ornamental purposes, jewelry (cabochons), and as a collector's specimen. Historically used for making tools and seals.

Geological facts

Jasper is an opaque variety of chalcedony. The name comes from the Greek word 'iaspis', meaning spotted stone. It has been a popular gemstone since ancient times.

Field identification & locations

Identify in the field by its conchoidal fracture and extreme hardness (it will scratch glass). Commonly found in riverbeds, deserts, and volcanic regions globally.