sedimentary
Jasper with Quartz Veins
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Hardness: 6.5-7 on Mohs scale; Color: Reddish-brown, purple, and white; Luster: Vitreous to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.9
- Hardness
- 6
- Color
- Reddish-brown, purple, and white
- Luster
- Vitreous 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 Mohs scale; Color: Reddish-brown, purple, and white; Luster: Vitreous to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.9
Formation & geological history
Formed from the deposition of silica-rich fluids within cracks of sedimentary or volcanic rocks. The 'brecciated' or veined appearance occurs as the host rock fractures and is later healed by secondary quartz precipitation.
Uses & applications
Used primarily for lapidary work, jewelry (cabochons and beads), decorative ornaments, and as a popular specimen for rock collectors.
Geological facts
Jasper is an opaque variety of chalcedony. The streaks and veins indicate different generations of mineral growth, often telling a complex history of hydrothermal activity in the Earth's crust.
Field identification & locations
Identify in the field by its hardness (cannot be scratched by a steel knife) and its distinct waxy luster on fracture surfaces. Often found in riverbeds or coastal gravels where harder minerals concentrate.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite
sedimentary