Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
Rock Type: sedimentary

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
Mode: Standard