Chert (and/or River Pebble)
Microcrystalline quartz (SiO2)
Category
Browse igneous or sedimentary (water worn) specimens identified by the Rock Identifier community.
Chert (and/or River Pebble)
Microcrystalline quartz (SiO2)
Sandstone (Quartzite-rich River Cobble)
Clastic sedimentary rock (primarily SiO2)
Chert (Polished River Pebble)
Chert (SiO2)
Chert (River Pebble)
Microcrystalline silica (SiO2)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Sandstone (with Siltstone/Greywacke variations)
Sedimentary Rock (Clastic)
White quartz pebble
Quartz (silicon dioxide, SiO₂), likely milky quartz
Quartz Pebble
Silicon Dioxide (SiO2)
Beach Pebbles and Quartz Aggregates
Quartz pebbles and biogenic fragments (SiO2, CaCO3)
Conglomerate
Conglomerate (Sedimentary Clastic Rock)
Jasper with Hematite Inclusions
Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3)
River Cobble (Quartzite / Sandstone)
Quartzite / Siliciclastic Sedimentary Rock
Gneiss (Schistose)
Gneiss
Conglomerate
Conglomerate (SiO2 primary clasts with lithic matrix)
Granite Pebble
Granite (Plutonic Igneous Rock)
Chert (Black Flint)
Cryptocrystalline Quartz (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
Yellow Quartz / Citrine Quartz
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
White Quartz Pebble
Silicon Dioxide (SiO2) - Quartz
River Cobble (likely Basalt or Metagraywacke)
Non-specific water-worn lithic fragment
Banded Chert
Silicon dioxide (SiO2) with impurities
Granite
Phaneritic plutonic rock (composed of quartz, feldspar, and mica)
Milky Quartz Pebble
Silicon Dioxide (SiO2)
Milky Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Ruby (varietal of Corundum)
Corundum (Al2O3:Cr)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (Yellow/Citrine variety)
Silicon Dioxide (SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
White Quartz Pebble
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Yellow or Honey Quartz
Silicon Dioxide (SiO2)
Rounded gray pebble, likely limestone or fine-grained basalt
Indeterminate from image; possible micritic limestone (calcite, CaCO₃) or basalt (plagioclase, pyroxene, minor oxides)
Granite Pebble
Granite (composed primarily of Quartz SiO2, Feldspar KAlSi3O8, and Biotite/Hornblende)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Conglomerate
Conglomerate
Red Jasper (River Stone)
Jasper (Silicon Dioxide, SiO2 plus iron oxide inclusions)
Pebble
Lithic fragment / Sedimentary clast