sedimentary
Jasper and Chert Conglomerate
Ferruginous Microcrystalline Quartz (SiO2)
Hardness: 6.5-7 (Mohs scale); Color: Brownish-red to cream/yellow; Luster: Dull to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.9
- Hardness
- 6
- Color
- Brownish-red to cream/yellow
- 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 (Mohs scale); Color: Brownish-red to cream/yellow; Luster: Dull to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.9
Formation & geological history
Formed through the accumulation of silica-rich sediments in ancient marine or fluvial environments. The red coloring is due to iron oxide inclusions (hematite). This specimen appears to be a stream-tumbled river rock, smoothed by water erosion.
Uses & applications
Primarily used as decorative stones, lapidary materials for tumbling and polishing, and as landscaping gravel or construction aggregate.
Geological facts
Jasper has been used as a gemstone since antiquity and was mentioned in many historical texts. The red variations are often referred to as 'blood of the earth' in various folklores.
Field identification & locations
Identify in the field by its hardness (it will scratch glass), smooth water-worn surface, and lack of visible crystals. Commonly found in riverbeds, glacial till, and coastal areas.
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