sedimentary

Jasper

Silicon Dioxide (SiO2) with impurities

Hardness: 6.5–7 on Mohs scale; Color: Green, brown, and reddish-tan; Luster: Vitreous to dull; Crystal structure: Hexagonal (trigonal microcrystalline); Cleavage: None (conchoidal fracture).

Hardness: 6
Color: Green, brown, and reddish-tan
Luster: Vitreous to dull

Identified May 25, 2026More sedimentary →

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Physical properties

Hardness: 6.5–7 on Mohs scale; Color: Green, brown, and reddish-tan; Luster: Vitreous to dull; Crystal structure: Hexagonal (trigonal microcrystalline); Cleavage: None (conchoidal fracture).

Formation & geological history

Formed when fine particulate materials (silica) are deposited in volcanic ash or sediments, bonded by silica-rich waters. The presence of iron oxides or chlorite creates the distinct green and brown banding.

Uses & applications

Used primarily in jewelry (beads, cabochons), lapidary art, and as decorative pocket stones or healing crystals in metaphysical practices.

Geological facts

Jasper is known as an 'opaque' variety of chalcedony. It has been used for millennia; ancient civilizations used it for cylinder seals and amulets due to its durability.

Field identification & locations

Field identification involves checking for opaqueness (jasper does not let light through), a smooth waxy feel when polished, and a characteristic conchoidal fracture pattern. Common in riverbeds and volcanic regions worldwide.