Red Sandstone
Arenite (primarily composed of SiO2 with Fe2O3 cement)
Category
Browse sedimentary rock (possibly composed of various minerals) specimens identified by the Rock Identifier community.
Red Sandstone
Arenite (primarily composed of SiO2 with Fe2O3 cement)
Gneiss (specifically a Granitic Gneiss)
Gneiss (typically composed of Quartz, Feldspar, and Mica/Amphiboles)
Shale
Shale (fine-grained clastic sedimentary rock)
Turquoise
Turquoise (Hydrated phosphate of copper and aluminium) CuAl6(PO4)4(OH)8·4H2O
River Siltstone Pebble
Siltstone (primarily composed of silica and clay minerals)
Shale
Shale (Sedimentary rock composed of mud/clay minerals)
Basalt
Mafic Igneous Rock (composed of plagioclase feldspar and pyroxene)
Sandstone
Sandstone (lithified arenite/wacke)
Shale or Slate with Quartz Veins
Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins
Chert (Flint)
Microcrystalline Quartz (SiO2)
Red Jasper (possibly)
Jasper (a variety of Chalcedony, SiO2)
Man-made Synthetic Material (Plastic/Composite)
Acrylonitrile Butadiene Styrene (ABS) or High-Impact Polystyrene (HIPS)
Red Sandstone
Arenite (primarily Quartz SiO2 with Hematite Fe2O3 cement)
Sandstone
Arenite
Orange Calcite (likely polished specimen)
Calcite
Sandstone (Ferruginous/Banded)
Clastic Terrigenous Sandstone (SiO2 with Fe2O3 cement)
Unknown Rock Specimen
Greisen
Greisen
Chert (Nodule)
Chert (composition: SiO2)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Dragon Stone
Argillaceous Sedimentary Rock (Ohko Stone)
Limestone (Brecciated/Recrystallized)
Calcium Carbonate (CaCO3)
Red Jasper (possibly Brecciated)
Jasper (Silicon Dioxide, SiO2)
Quartz Geode (likely within Limestone or Dolomite matrix)
Quartz (SiO₂)
Quartz
Silicon Dioxide (SiO2)
Granite Pebble
Granite (Phaneritic Quartz-Feldspar Rock)
Sandstone
Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)
Chert
Chert (variant of microcrystalline quartz)
Conglomerate (Puddingstone)
Conglomerate (specifically, clastic sedimentary rock)
Sandstone (Red Flagstone)
Clastic sedimentary rock (primarily Quartz - SiO2)
Sandstone or Limestone
Arenite or Calcareous Sedimentary Rock
Red Jasper (possibly Agatized Jasper)
Jasper (Silicon Dioxide, SiO2 with Fe2O3 inclusions)
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
Soapstone
Steatite (primarily composed of Talc, Mg₃Si₄O₁₀(OH)₂)
Banded Gneiss (with possible weathered sulfide or iron staining)
Gneiss, potentially with iron oxide/hydroxide staining (e.g., limonite) or weathered sulfides
River Siltstone / Mudstone Pebble
Siltstone (composed of mixed silicate and carbonate minerals)
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
Siltstone/Sandstone (possibly Wonderstone or Picture Sandstone)
Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide inclusions)
Sandstone Concretion
Sedimentary concretion
Greisen (Quartz-Muscovite-Turretine Rock)
Greisen
Quartzite
Quartzite (composed primarily of SiO2)
Schist (Biotite Schist)
Biotite-bearing Schist (K(Mg,Fe)3AlSi3O10(F,OH)2)