sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) - Opaque variety of Chalcedony/Quartz
Hardness: 6.5-7.0 (Mohs scale); Color: Mustard yellow, golden brown; Luster: Vitreous to dull; Crystal structure: Trigonal (Microcrystalline); Cleavage: None; Specific gravity: 2.6-2.9
- Hardness
- 6
- Color
- Mustard yellow, golden brown
- Luster
- Vitreous to dull
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7.0 (Mohs scale); Color: Mustard yellow, golden brown; Luster: Vitreous to dull; Crystal structure: Trigonal (Microcrystalline); Cleavage: None; Specific gravity: 2.6-2.9
Formation & geological history
Formed from silica-rich fluids depositing in volcanic ash or sedimentary beds over millions of years. The yellow color is primarily due to the presence of goethite or iron oxide inclusions during the petrification process.
Uses & applications
Used widely in decorative arts, jewelry (cabochons and beads), spiritual/holistic practices, and as a durable material for mosaics and small carvings.
Geological facts
Jasper has been used since antiquity; it was known as the 'Supreme Nurturer' in ancient times. The yellow variety specifically was historically used by travelers as a stone of protection.
Field identification & locations
Identify in the field by its opaque nature (unlike translucent Citrine), smooth conchoidal fracture, and inability to be scratched by a steel knife. Found commonly in South Africa, Madagascar, Australia, and the USA.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone (Quartz-rich)
Arenite (SiO2)
sedimentary
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
sedimentary