sedimentary

Yellow Jasper

Silicon dioxide (SiO2)

Hardness: 6.5-7 (Mohs); Color: Yellow to mustard yellow; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal) microcrystalline quartz; Cleavage: None; Specific Gravity: 2.58-2.91.

Hardness: 6
Color: Yellow to mustard yellow
Luster: Vitreous to greasy

Identified April 1, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Yellow to mustard yellow; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal) microcrystalline quartz; Cleavage: None; Specific Gravity: 2.58-2.91.

Formation & geological history

Jasper forms from the precipitation of silica from water or volcanic ash. This variety gets its yellow color from goethite or iron oxide inclusions. It is often found in sedimentary deposits or as a secondary mineral in volcanic rocks.

Uses & applications

Used primarily for jewelry (cabochons and beads), decorative carvings, and as a popular collector's stone. Historically used for making tools due to its conchoidal fracture.

Geological facts

Jasper is an opaque variety of chalcedony. Historically, yellow jasper was used as a 'stone of protection' for travelers. It has been a popular gemstone since ancient times, often used in Babylonian and Egyptian jewelry.

Field identification & locations

Identify by its waxy luster, opacity (unlike citrine which is transparent), and yellow-to-brownish hue. It is commonly found in river beds or as pebbles in desert environments worldwide.