Ferruginous Sandstone (with ripple marks)
Arenite with Iron-Oxide (Fe2O3) cement
sedimentary
Category
Sedimentary Rock (Specifically A Clastic Sedimentary Rock Formed Into A Cobble)
Browse sedimentary rock (specifically a clastic sedimentary rock formed into a cobble) specimens identified by the Rock Identifier community.
Quartzite
Quartzite (mainly SiO2)
metamorphic
Dendritic Siltstone (or Mudstone)
Siltstone with Manganese Oxide dendrites
sedimentary
Granite Cobble
Felsic Intrusive Igneous Rock (Granite)
igneous
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Graywacke (Sandstone)
Graywacke Sandstone
sedimentary
River Cobble (Quartzite)
Meta-orthoquartzite
metamorphic
Shale
Shale (Consolidated fine-grained clay/silt)
sedimentary
Chert Nodule (Commonly known as a Flint or River Cobble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Red Sandstone
Arenite (primarily composed of SiO2 with Fe2O3 cement)
sedimentary
Greywacke with Quartz Veins
Lithic Sandstone (Greywacke) with SiO2 inclusions
sedimentary
River Cobble (Conglomerate context)
Unconsolidated Fluvial Alluvium (comprised of various lithologies like Quartzite, Granite, or Basalt)
sedimentary
Ferruginous Quartz Cobble
Silicon Dioxide (SiO2) with Iron Oxide inclusions
mineral
Chert (Yellow/Tan Variety)
Chert (SiO2)
sedimentary
Amber-bearing Coal/Sedimentary Rock
Bituminous coal or carbonaceous siltstone with Fossilized Tree Resin (C10H16O)
sedimentary
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Quartzite with Chlorite/Epidote
Metamorphosed Quartzite (SiO2)
metamorphic
Sandstone
Sandstone (clastic sedimentary rock, composed predominantly of sand-sized minerals or rock fragments)
Sedimentary Rock
Ferruginous Sandstone (Ironstone)
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
sedimentary
Gneiss (specifically Biotite Gneiss)
Gneiss (high-grade metamorphic rock primarily composed of Silicates)
metamorphic
Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Dalmation Stone (often called Dalmatian Jasper)
Antiperthite-rich Microgranite
igneous
Jasper (specifically a banded or dark variety)
Silicon Dioxide (SiO2) with impurities
sedimentary
Wishing Stone (Basalt with Quartz Vein)
Basalt containing a microcrystalline quartz (SiO2) or calcite vein
igneous
Chert (specifically Green Chert/Jasper)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Granite Cobble
Plutonic Igneous Rock (Granitic)
igneous
Green Sandstone
Glauconitic Sandstone
sedimentary
Pyrite in Shale
Iron Disulfide (FeS2)
mineral
Red Sandstone
Arenite (predominantly SiO2 with Fe2O3)
sedimentary
Granite Cobble
Phaneritic Felsic Igneous Rock
igneous
Sandstone or Limestone
Arenite or Calcareous Sedimentary Rock
Sedimentary
Granite Cobble
Granite (Phaneritic Igneous Rock)
igneous
Gastropod Steinkern (Internal Mold Fossil)
Gastropoda (Class); Internal mold or 'Steinkern' composed of Calcium Carbonate (CaCO3) or Sedimentary matrix
sedimentary
Granite Cobble
Felsic intrusive igneous rock
igneous
Gneiss (specifically a Granitic Gneiss)
Gneiss (Composition: Quartz, Feldspar, Mica)
metamorphic
Yellow Quartzite (River Stone)
Quartzite (primarily SiO2)
metamorphic
Herkimer Diamond
Quartz (Silica - SiO2)
mineral
Granite Cobble
Phaneritic Felsic Igneous Rock
igneous
Quartzite Cobble
Quartzite (primarily SiO2)
metamorphic
Sandstone
Arenite (a specific type of sandstone with less than 15% matrix)
Sedimentary rock
Muscovite Mica
Muscovite (KAl₂(AlSi₃O₁₀)(F,OH)₂))
Mineral
Smoky Quartz (with possible Feldspar inclusions)
Silicon Dioxide (SiO2)
mineral