sedimentary
Mixed River Pebbles (Jasper, Hematite, and Quartzites)
Silicon dioxide (Jasper/Quartz) and Iron oxide (Hematite)
Hardness ranges from 5.5 to 7 on the Mohs scale. Colors include reddish-brown, dark grey, and metallic silver. Luster varies from dull to metallic and waxy. Crystal structure is microcrystalline quartz and rhombohedral hematite.
Identified More sedimentary →
Explore Mixed River Pebbles (Jasper, Hematite, and Quartzites) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness ranges from 5.5 to 7 on the Mohs scale. Colors include reddish-brown, dark grey, and metallic silver. Luster varies from dull to metallic and waxy. Crystal structure is microcrystalline quartz and rhombohedral hematite.
Formation & geological history
Formed through weathering, erosion, and aqueous transport of various mineral-rich parent rocks, subsequently rounded and polished by water action in riverbeds over millions of years.
Uses & applications
Used primarily in lapidary work, landscaping, decorative landscaping, and as pocket specimens for amateur rockhounds.
Geological facts
River pebbles often accumulate in placers where heavy minerals like hematite concentrate alongside durable silicates like jasper due to their specific gravity.
Field identification & locations
Found globally in active riverbeds, alluvial plains, and ancient gravel terraces. Easily identified in the field by their smooth, water-worn shapes and varied mineralogy.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Banded Siltstone / Mudstone Pebble
Siltstone / Argillite
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary