sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron hydroxides (Goethite)

Hardness: 6.5-7 on Mohs scale. Color: Mustard yellow to brownish-gold. Luster: Dull to vitreous when wet/polished. Crystal structure: Microcrystalline/Cryptocrystalline. Cleavage: None (conchoidal fracture). Specific gravity: 2.6-2.9.

Hardness: 6
Color: Mustard yellow to brownish-gold
Luster: Dull to vitreous when wet/polished

Identified May 1, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica-rich fluids in volcanic ash or sedimentary beds. The yellow coloration comes from concentrations of iron minerals like goethite or limonite. Found in ancient riverbeds and volcanic deposits ranging from several million up to billions of years old.

Uses & applications

Mainly used for lapidary work, jewelry (cabochons, beads), decorative carvings, and spiritual/metaphysical collecting.

Geological facts

Jasper is an opaque variety of chalcedony. Yellow jasper was historically used by ancient civilizations for amulets and protective talismans. It is often found as water-worn pebbles in secondary deposits.

Field identification & locations

Identify in the field by its opacity (it will not let light through even at thin edges, unlike agate), its smooth waxy feel when wet, and its inability to be scratched by a steel knife. Common in diverse global locations including the USA, South Africa, and India.

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