sedimentary

Jasper (Brown Iron-Rich Variety)

Silicon Dioxide (SiO2) with Fe2O3 (Iron Oxide/Crystalline Quartz)

Hardness: 6.5–7 on Mohs scale; Color: Dark brown to reddish-brown; Luster: Vitreous to waxy; Crystal structure: Microcrystalline/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58–2.91

Hardness: 6
Color: Dark brown to reddish-brown
Luster: Vitreous to waxy

Identified March 20, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the deposition of silica-rich fluids in volcanic ash or sedimentary beds, often through the replacement of organic material or mineral leaching. Its age can range from tens of millions to billions of years depending on the stratigraphic unit.

Uses & applications

Used primarily in lapidary work for cabochons, beads, and decorative carvings. It is also used as a gemstone in jewelry and collected as a tumbling stone.

Geological facts

Jasper is an opaque variety of chalcedony. The name comes from the Greek word 'iaspis', meaning 'spotted stone'. In ancient times, brown jasper was believed to offer the wearer protection and grounding energy.

Field identification & locations

Identify in the field by its opaque nature (unlike agate which is translucent), its smooth conchoidal fracture, and it being hard enough to scratch glass. Commonly found in riverbeds and dry washes in volcanic regions.

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