Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides (Goethite/Limonite)
Rock Type: sedimentary

Physical Properties
Hardness: 6.5-7 on Mohs scale; Color: Mustard yellow, golden brown; Luster: Vitreous to waxy; Structure: Microcrystalline/cryptocrystalline (trigonal); Cleavage: None; Specific Gravity: 2.58-2.91.
Formation & Geological History
Formed through the deposition of silica from mineral-rich waters into sedimentary rock pores or volcanic ash. The yellow color is caused by the inclusion of iron oxide or goethite during formation. Most deposits range from the Paleozoic to Cenozoic eras.
Uses & Applications
Commonly used as a pocket stone for metaphysical purposes, lapidary work (cabochons and beads), and ornamental carvings. It is also a popular collector's item for those interested in quartz varieties.
Geological Facts
Jasper is an opaque variety of chalcedony. Yellow Jasper is often associated with sun energy and was historically used by various cultures as a protective stone and a travel talisman.
Field Identification & Locations
Identify by its complete opacity (unlike yellow agate), waxy feel when polished, and high hardness (will scratch glass). It is commonly found in riverbeds and coastal regions of South Africa, Brazil, and the USA (Oregon/Idaho).
Identified on: 4/13/2026
Mode: Standard