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

Physical Properties
Hardness: 6.5-7 (Mohs scale); Color: Yellow, mustard, ochre-gold; Luster: Dull to Vitreous/Waxy; Crystal Structure: Microcrystalline (Trigonal); Cleavage: None; Specific Gravity: 2.58-2.91
Formation & Geological History
Formed through the accumulation of silica-rich fluids that penetrate through volcanic cracks or sedimentary layers. The yellow color is caused by the inclusion of iron oxide minerals like goethite or limonite.
Uses & Applications
Commonly used for lapidary work, jewelry (cabochons and beads), decorative ornaments, and as a popular meditation or 'healing' stone in spiritual practices.
Geological Facts
Jasper is an opaque variety of chalcedony. In ancient times, it was considered a stone of protection and was often referred to as the 'Rain Bringer' in Native American traditions.
Field Identification & Locations
Identify in the field by its opacity (unlike translucent agate) and smooth, conchoidal fracture. Often found in riverbeds or coastal gravels where harder minerals concentrate. Common in the Western USA, Brazil, and India.
Identified on: 4/13/2026
Mode: Standard