sedimentary

Jasper

Silicon dioxide (SiO2)

Hardness: 6.5-7 (Mohs); Color: Reddish-brown, earthy tones; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline/cryptocrystalline); Cleavage: None; Specific gravity: 2.58-2.91

Hardness: 6
Color: Reddish-brown, earthy tones
Luster: Vitreous to dull

Identified June 1, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Reddish-brown, earthy tones; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline/cryptocrystalline); Cleavage: None; Specific gravity: 2.58-2.91

Formation & geological history

Formed through the settlement of silica in water or through the replacement of organic material with silica. It is often found in prehistoric sedimentary formations.

Uses & applications

Used primarily in lapidary work for jewelry, ornaments, and pocket stones. Historically used for making tools due to its conchoidal fracture.

Geological facts

Jasper have been used by humans for thousands of years; it was a favorite gem in the ancient world and is mentioned in various historical and religious texts.

Field identification & locations

Identify by its hardness (will scratch glass), opaque nature, and smooth, waxy surface when polished. Commonly found in riverbeds and desert environments.