sedimentary

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Hardness: 6.5-7 (Mohs scale); Color: Yellowish-brown with darker veining; Luster: Waxy to dull; Crystal Structure: Trigonal (Microcrystalline); Cleavage: None (Conchoidal fracture); Specific Gravity: 2.6-2.9.

Hardness: 6
Color: Yellowish-brown with darker veining
Luster: Waxy to dull

Identified June 25, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the infiltration of silica-rich fluids into sedimentary or volcanic material, where iron inclusions provide the yellow tint. It often forms in hydrothermal environments or deep-sea sedimentary layers.

Uses & applications

Commonly used as a gemstone for jewelry (cabochons, beads), decorative ornaments, and by lapidary hobbyists for tumbling. It has historical use as a seal or amulet.

Geological facts

The word 'jasper' comes from the Greek word 'iaspis', meaning spotted stone. It is a dense, opaque variety of chalcedony that can contain up to 20% foreign material, which determines its color and pattern.

Field identification & locations

Identify by its opacity (does not transmit light), smooth waxy feel, and extreme hardness (will scratch glass). Commonly found in riverbeds or coastal areas in the Western USA, Brazil, and India.