sedimentary
Mixed River Pebbles
Clastic Sedimentary Alluvial Deposit / Polymictic Conglomerate Clasts
Varied hardness (mostly 5-7 Mohs), colors ranging from white, tan, and grey to black. Textures include smooth water-worn surfaces and some jagged fractures. Predominantly composed of quartz, feldspar, and various lithic fragments.
Identified More sedimentary →
Explore Mixed River Pebbles in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Varied hardness (mostly 5-7 Mohs), colors ranging from white, tan, and grey to black. Textures include smooth water-worn surfaces and some jagged fractures. Predominantly composed of quartz, feldspar, and various lithic fragments.
Formation & geological history
Formed through the mechanical weathering and transport of diverse parent rocks (igneous, metamorphic, and sedimentary) in a high-energy fluvial (river) environment, leading to rounded shapes over time.
Uses & applications
Used primarily in landscaping, decorative ground cover, construction aggregate, and as 'pocket stones' for amateur collectors.
Geological facts
River pebbles act as natural records of a region's geology; a single handful can contain rocks that formed millions of years apart in vastly different environments.
Field identification & locations
Identify by their rounded, water-polished edges and diverse mineralogy. Commonly found in riverbeds, glacial moraines, and coastal beaches. Look for 'clasts' (individual rocks) with distinct banding or crystal structures.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary