sedimentary

Jasper

Silicon dioxide (SiO2) with iron inclusions

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale; Color: Reddish-brown; Luster: Vitreous to dull; Crystal structure: Microcrystalline/Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

Hardness: 6
Color: Reddish-brown
Luster: Vitreous to dull

Identified April 9, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Reddish-brown; Luster: Vitreous to dull; Crystal structure: Microcrystalline/Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

Formation & geological history

Formed from silica-rich sediment or volcanic ash deposits where silica precipitates from water. Its red-brown color is typically due to iron oxide (hematite) inclusions within the quartz matrix. It can range from Precambrian to modern in age.

Uses & applications

Used primarily as a gemstone for jewelry, in lapidary arts for cabochons, and as a decorative stone in carvings and mosaics.

Geological facts

Jasper has been used as a gemstone since antiquity; it was mentioned in various ancient cultures including the Minoans on Crete and ancient Egyptians who used red jasper for amulets.

Field identification & locations

Identify by its hardness (it will scratch glass), its opaque nature, and smooth conchoidal fractures. Commonly found in riverbeds or near ancient volcanic regions. It is a common find for beachcombers and rockhounds in various global locations.