sedimentary

Jasper

Silicon dioxide (SiO2)

Hardness: 6.5-7 (Mohs); Color: Mottled green, dark brown, and olive; Luster: Vitreous to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.9

Hardness: 6
Color: Mottled green, dark brown, and olive
Luster: Vitreous to waxy

Identified April 1, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Mottled green, dark brown, and olive; Luster: Vitreous to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.9

Formation & geological history

Formed from the deposition of silica from water found in hydrothermal vents or sedimentary environments. It often contains impurities like iron or clay that create its unique patterns. Ages range from millions to over a billion years old.

Uses & applications

Commonly used in lapidary arts for decorative items, jewelry (cabochons), talismans, and as polished river stones for collections.

Geological facts

Jasper is an opaque variety of chalcedony. It has been used by ancient civilizations for seals and ornamentation and is often associated with strength and grounding in symbolic traditions.

Field identification & locations

Identify in the field by its opacity (even on thin edges) and its inability to be scratched by a steel knife. It is common in riverbeds, canyons, and coastal areas with volcanic history.