sedimentary

Jasper

Silicon dioxide (SiO2) with impurities, microcrystalline quartz

Hardness: 6.5 to 7 on the Mohs scale; Color: Red, brown, yellow, green, or multicolored; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline/cryptocrystalline quartz); Cleavage: None, exhibits conchoidal fracture; Specific gravity: 2.58 to 2.91

Hardness: 6
Color: Red, brown, yellow, green, or multicolored
Luster: Vitreous to dull

Identified July 29, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the silification of sedimentary or volcanic rocks where silica-rich fluids replace organic material or fill cavities over millions of years.

Uses & applications

Used in ornamental carvings, jewelry, lapidary arts, and as decorative aggregate.

Geological facts

Jasper has been used since ancient times to create seals, signet rings, and intricate talismans. Red varieties get their distinct color from iron oxide inclusions.

Field identification & locations

Can be identified in the field by its hardness (scratches glass), waxy to dull luster, and smooth conchoidal fracture. Commonly found in riverbeds, glacial tills, and areas with ancient volcanic or hydrothermal activity.

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