sedimentary

Jasper (Yellow/Brown variety)

Silicon Dioxide (SiO2) with iron oxide impurities

Hardness: 6.5-7 (Mohs scale); Color: Yellowish-brown to mustard; Luster: Waxy to vitreous when wet; Crystal Structure: Microcrystalline/Cryptocrystalline (Trigonal); Cleavage: None (Conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Yellowish-brown to mustard
Luster: Waxy to vitreous when wet

Identified March 29, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica-rich fluids in cracks or voids within other rocks, often associated with volcanic ash or sedimentary processes. Can be found in various strata ranging from Precambrian to more recent geological eras.

Uses & applications

Predominantly used as a gemstone for jewelry (cabochons), lapidary art, aquarium decor, and metaphysical collecting.

Geological facts

Jasper is an opaque variety of chalcedony. The name comes from the Greek 'iaspis', meaning 'spotted stone.' It is historically valued for its supposed protective qualities and ability to nurture.

Field identification & locations

Identify in the field by its opacity (it will not let light through like agate), its smoothness from river tumbling, and its inability to be scratched by a steel knife. Common in riverbeds and coastal regions globally.

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