sedimentary

Jasper

Silicon Dioxide (SiO2)

Hardness: 6.5-7 (Mohs scale), Color: Variegated greens, pinks, and creams, Luster: Vitreous to dull (waxy when polished), Crystal Structure: Microcrystalline/Cryptocrystalline (Trigonal), Cleavage: None, Specific Gravity: 2.58-2.91

Hardness: 6

Identified June 21, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica from water solutions or volcanic ash into sedimentary environments; often found in Precambrian to more recent geological layers. This specific specimen shows a 'polychrome' or multi-colored pattern common in Madagascar jaspers.

Uses & applications

Used primarily in lapidary arts for decorative objects, jewelry, tumbled stones, and as a collector's specimen.

Geological facts

Jasper is an opaque variety of chalcedony. Historically, it was revered as a 'supreme nurturer' and has been used in seals and amulets since ancient Mesopotamian civilizations.

Field identification & locations

Identify by its opacity (it will not let light pass through like agate), its hardness (will scratch glass), and its characteristic smooth, waxy feel when polished. Commonly found in riverbeds or coastal deposits.