sedimentary

Yellow Jasper

Cryptocrystalline Quartz (SiO2) with iron inclusions

Hardness: 6.5-7 on Mohs scale; Color: Mustard yellow, brown, and reddish zones; Luster: Dull to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Mustard yellow, brown, and reddish zones
Luster: Dull to waxy

Identified February 5, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed via the deposition of silica from water in sedimentary environments or volcanic ash beds. The yellow color is primarily caused by goethite or limonite iron inclusions. This specimen likely dates from any period between the Paleozoic and Cenozoic eras.

Uses & applications

Commonly used for lapidary work, cabochons, decorative beads, and ornamental carvings. Historically used for making stone tools due to its sharp conchoidal fracture.

Geological facts

Jasper is an opaque variety of chalcedony. In ancient times, jasper was believed to provide protection and was often used in amulets. 'Yellow Jasper' specifically is sometimes nicknamed the 'stone of discernment'.

Field identification & locations

Identifiable in the field by its opacity, smooth conchoidal fracture, and inability to be scratched by a steel knife. Frequently found in riverbeds or desert regions of the Western United States, Brazil, and India. Collectors should look for vibrant banding or consistent coloration.

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