Rock Identifier
Yellow Jasper (Silicon Dioxide (SiO2) with iron inclusions) — sedimentary
sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron inclusions

Hardness: 6.5-7 (Mohs scale), Color: Mustard yellow to golden brown, Luster: Vitreous to waxy, Crystal Structure: Trigonal (Microcrystalline), Cleavage: None/Conchoidal fracture, Specific Gravity: 2.58-2.91

Hardness
6
Identified More sedimentary

Identify your own rocks.

Get a report just like this from any photo, free.

Physical properties

Hardness: 6.5-7 (Mohs scale), Color: Mustard yellow to golden brown, Luster: Vitreous to waxy, Crystal Structure: Trigonal (Microcrystalline), Cleavage: None/Conchoidal fracture, Specific Gravity: 2.58-2.91

Formation & geological history

Formed via the deposition of silica from water-saturated solutions in volcanic ash or sedimentary environments. The yellow color is derived from iron oxide (goethite) inclusions. Usually found as nodules or in cracks during volcanic or sedimentary processes.

Uses & applications

Used primarily as a decorative stone, in lapidary work for cabochons, jewelry, and as a collector's specimen. Historically used for making tools and seals due to its toughness.

Geological facts

Yellow Jasper is sometimes referred to as the 'Nurturing Stone.' It is a cryptocrystalline variety of quartz, meaning its crystals are so small they can only be seen under extreme magnification. Large beds are found in river deposits where they have been tumbled and polished naturally.

Field identification & locations

Identify by its bright yellow color, opaque nature (unlike yellow chalcedony which is translucent), and smooth, waxy texture when wet or polished. Look for conchoidal fractures and a lack of visible grain. Common in areas with ancient volcanic activity and riverbeds.