sedimentary

Yellow Jasper

Silicon Dioxide (SiO2)

Hardness: 6.5-7.0 (Mohs scale); Color: Mottle yellow and brown; Luster: Vitreous to waxy; Structure: Microcrystalline; Cleavage: None; Specific Gravity: 2.58–2.91

Hardness: 6
Color: Mottle yellow and brown
Luster: Vitreous to waxy

Identified June 19, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7.0 (Mohs scale); Color: Mottle yellow and brown; Luster: Vitreous to waxy; Structure: Microcrystalline; Cleavage: None; Specific Gravity: 2.58–2.91

Formation & geological history

Formed when silica-rich fluids permeate through volcanic ash or sediment, often containing clay or iron oxides that provide the yellow hue. Typically associated with hydrothermal activity or groundwater deposition.

Uses & applications

Used primarily in lapidary work, jewelry (beads, cabochons), and as a collector's stone. It is also historically used for ornamental seals and artifacts.

Geological facts

Jasper is an opaque variety of chalcedony. The name comes from the Greek word 'iaspis', meaning 'spotted stone.' Yellow jasper has been used since ancient times as a symbol of protection and endurance.

Field identification & locations

Identify in the field by its opacity (unlike translucent agate) and conchoidal fracture. Commonly found in riverbeds, deserts, and volcanic regions. This specimen shows water-worn smoothing.