sedimentary

Jasper

Silicon Dioxide (SiO2)

Hardness: 6.5-7 (Mohs scale); Color: Variegated brown, tan, and black; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (Conchoidal fracture); Specific gravity: 2.58-2.91.

Hardness: 6
Color: Variegated brown, tan, and black
Luster: Vitreous to waxy

Identified March 25, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica from water-rich environments (often near volcanic vents or in sedimentary basins) into cracks and pockets. Over millions of years, the silica-rich mud or ash lithifies into stone. Its colors come from iron oxides and other mineral impurities.

Uses & applications

Commonly used in the jewelry industry for cabochons and beads, ornamental carvings, and as a decorative stone in landscaping or interior design. It is also a popular stone for tumbling and beginner rock collecting.

Geological facts

Jasper has been used as a gemstone since antiquity; it was known in the Greek, Roman, and Persian civilizations for its alleged healing properties and was often used to make cylinder seals and amulets. It is an opaque variety of chalcedony.

Field identification & locations

Identify in the field by its opacity (even on thin edges, light does not pass through) and its conchoidal fracture (smooth, curved chips like glass). This specimen appears to be water-worn or tumbled, likely found in a riverbed or gravel pit.