sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite or Iron Oxide inclusions
Hardness: 6.5–7 on the Mohs scale; Color: Mustard yellow to golden brown; Luster: Dull to waxy; Crystal Structure: Microcrystalline (Trigonal); Cleavage: None (Conchoidal fracture); Specific Gravity: 2.58–2.91
- Hardness
- 6
- Color
- Mustard yellow to golden brown
- Luster
- Dull to waxy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5–7 on the Mohs scale; Color: Mustard yellow to golden brown; Luster: Dull to waxy; Crystal Structure: Microcrystalline (Trigonal); Cleavage: None (Conchoidal fracture); Specific Gravity: 2.58–2.91
Formation & geological history
Formed through the deposition of silica from water or volcanic ash into cracks or cavities. Over geological time (often millions of years), the silica crystallizes into microcrystalline quartz. The yellow color is caused by the presence of iron-bearing minerals like goethite.
Uses & applications
Commonly used in lapidary work for making cabochons, beads, and ornamental carvings. It is popular in the jewelry industry for its earth tones and is also a favorite for metaphysical practitioners and rock collectors.
Geological facts
Jasper is an opaque variety of chalcedony. Historically, it was used by ancient civilizations for seal stones and amulets. Because it is so hard and dense, it can take a high polish that lasts for years.
Field identification & locations
Identify in the field by its opaque nature (it does not transmit light even on thin edges), its characteristic conchoidal fracture (smooth, curved breaks), and its inability to be scratched by a steel knife. It is commonly found in riverbeds, deserts, and volcanic regions globally, particularly in the western USA, Brazil, and India.
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