Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Rock Type: sedimentary

Yellow Jasper

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Yellow to mustard-gold; Luster: Dull to waxy; Crystal Structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.58–2.91

Formation & Geological History

Formed from the deposition of silica from water or volcanic ash into sedimentary rocks over millions of years. The yellow color is primarily due to the inclusion of iron oxides (goethite).

Uses & Applications

Used primarily for lapidary work, jewelry (cabochons), talismans, and as decorative stones for aquarium or garden landscapes.

Geological Facts

Jasper is an opaque variety of chalcedony. Yellow Jasper is known historically as a traveler\'s stone that was believed to provide protection and discernment during long journeys.

Field Identification & Locations

Identify by its complete opacity (unlike agate), smooth waxy feel when tumbled, and yellow/tan streak. Commonly found in riverbeds or coastal areas where volcanic activity occurred.

Identified on: 4/15/2026

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