sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron hydroxides

Hardness: 6.5-7.0 (Mohs scale), Color: dull mustard yellow to golden brown, Luster: dull to vitreous, Crystal Structure: Trigonal (microcrystalline/cryptocrystalline), Cleavage: none (conchoidal fracture), Specific Gravity: 2.58-2.91

Hardness: 6

Identified July 9, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the deposition of silica-rich fluids in volcanic or sedimentary environments, often associated with hydrothermal activity. The yellow color is due to the presence of goethite or other iron hydroxides. It can form in various geological ages ranging from Precambrian to Cenozoic.

Uses & applications

Commonly used for lapidary work, jewelry (cabochons), carvings, metaphysical collecting, and as a durable material for decorative ornamentation.

Geological facts

Yellow jasper is a variety of chalcedony that is opaque due to high mineral inclusions. It has been used since ancient times for both ornamental and protective amulets. It is often found in banded patterns known as Picture Jasper.

Field identification & locations

Identified in the field by its hardness (it will scratch glass), its opaque nature, and its distinct smooth, waxy fracture surface. Common locations include South Africa, India, USA (Oregon, Idaho), and Brazil.

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