sedimentary
Jasper with Quartz Veining
Silicon Dioxide (SiO2) - Opaque cryptocrystalline variety of Quartz
Hardness: 6.5-7 (Mohs scale); Color: Deep reddish-brown (from iron inclusions) with white to light-gray quartz veins; Luster: Dull to waxy when unpolished; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91
- Hardness
- 6
- Luster
- Dull to waxy when unpolished
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: Deep reddish-brown (from iron inclusions) with white to light-gray quartz veins; Luster: Dull to waxy when unpolished; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91
Formation & geological history
Formed through the infiltration of silica-rich fluids into sediment or volcanic ash. The red color suggests the presence of iron oxide (hematite). The veins indicate subsequent brittle fracturing where secondary quartz precipitated into cracks. Common in Precambrian and Paleozoic age deposits.
Uses & applications
Primarily used for lapidary work, jewelry (cabochons, beads), decorative ornaments, and as a popular specimen for rock tumbling and collecting.
Geological facts
In antiquity, red jasper was known as the 'rain-bringer' and was believed to drive away evil spirits. The white veins are often called 'quartz stringers' and are the result of tectonic stress that cracked the stone while it was underground.
Field identification & locations
Identify in the field by its hardness (cannot be scratched by a steel knife), smooth water-worn texture on beaches/riverbeds, and the presence of intersecting mineral veins. Commonly found on coastlines, particularly in areas like the Pacific Northwest or the Great Lakes.
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