sedimentary

Jasper Cross

Silicon Dioxide (SiO2) with iron oxide impurities

Hardness: 6.5-7 (Mohs scale); Color: Reddish-brown to earthy tones; Luster: Dull to vitreous; Crystal Structure: Microcrystalline/Cryptocrystalline (rhobohedral); Cleavage: None; Specific Gravity: 2.58-2.91

Hardness: 6
Color: Reddish-brown to earthy tones
Luster: Dull to vitreous

Identified March 28, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the infiltration of silica in clay or volcanic ash during sedimentary processes, often within hydrothermal or volcanic environments. Its age can range from hundreds of millions to billions of years depending on the stratigraphic layer.

Uses & applications

Commonly used in jewelry, small carvings, religious talismans, and ornamental lapidary work. It is valued for its ability to take a high polish and its durability.

Geological facts

Jasper is an opaque variety of chalcedony. The name 'jasper' is derived from the Greek word 'iaspis', meaning 'spotted stone.' Historically, red-hued jasper was associated with strength and protection in ancient Egyptian and Roman cultures.

Field identification & locations

Identify by its opacity (unlike translucent quartz), smooth conchoidal fracture, and inability to be scratched by a steel knife. It is commonly found globally, notably in the USA (Oregon/Idaho), India, and Madagascar. For collectors, look for unique patterns or deep saturation.

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