sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron hydroxides (Goethite)

Hardness: 6.5-7 (Mohs scale); Color: Opaque yellow to mustard brown; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91.

Hardness: 6
Color: Opaque yellow to mustard brown
Luster: Vitreous to waxy

Identified March 28, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the deposition of silica from water-rich environments like thermal springs or during the sedimentation of volcanic ash and silicate-rich fluids. It can date from various geological periods, often millions of years old, typically found in hydrothermal veins or sedimentary beds.

Uses & applications

Primarily used in jewelry (beads, cabochons), lapidary art, and ornamental carvings. Historically used for making tools and as a decorative stone in ancient architecture.

Geological facts

Jasper is an impure variety of silica; the yellow color is specifically caused by the presence of Goethite or other iron oxides. In ancient times, it was called the 'rain bringer' and was believed to protect travelers.

Field identification & locations

Identify in the field by its opaque nature (unlike translucent chalcedony), smooth waxy feel when weathered, and hardness (it will scratch glass). Commonly found in riverbeds or desert regions of India, Russia, Brazil, and the USA.

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