Sandstone
Arenite (composed primarily of SiO2)
Category
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Sandstone
Arenite (composed primarily of SiO2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Iron Oxide staining)
Limestone
Calcium Carbonate (CaCO3)
Sandstone (likely Quartzose type)
Clastic sedimentary rock (primarily SiO2)
Sandstone
Arenite (primarily SiO2 - Silicon Dioxide)
Granite
Granite (Felsic Plutonic Rock / SiO2 + Al2O3)
Sandstone (Ferruginous)
Arenite (complex silicate composition with iron oxides)
Porphyritic Basalt
Porphyritic Fine-grained Mafic Volcanic Rock
Pumice
Pumice (Vesicular Rhyolite/Dacite)
Vesicular Basalt (commonly mistaken for Slag)
Scoriaceous Basalt (composed primarily of Plagioclase Feldspar and Pyroxene)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Sandstone
Arenite
Basalt River Stone
Basalt
Sandstone (likely Arkosic)
Clastic Sedimentary Rock (Sandstone)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (Litharenite)
Opal
Hydrated Silica (SiO2·nH2O)
Basalt
Mafic volcanic rock (various silicate minerals including Pyroxene and Plagioclase)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Andesite Porphyry (River Cobble)
Porphyritic Andesite
Pumice
Pumice (Alveolar Rhyolite / Dacite / Andesite)
Slag (Industrial Glass/Metal Waste)
Artificial silicate/ferro-silicate byproduct
Sandstone (River Cobble)
Clastic Sedimentary Rock (primarily Quartz with Feldspar)
Chert (Tan/Yellow variety)
Microcrystalline quartz (SiO2)
Chert (Jasper variation)
Silicon dioxide (SiO2)
Jasper
Silicon dioxide (SiO2)
Ferruginous Quartz
Quartz with Iron Oxide inclusions (SiO2 + Fe2O3)
Chert / Flint
Microcrystalline Quartz (SiO2)
Chert (often called Flint in dark varieties)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Iron-stained)
Chert (Cryptocrystalline Silica, SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Sandstone (Greywacke/Lithic Sandstone)
Arenite / Lithic Sandstone
Sandstone (likely Arkose)
Arenite (composed mainly of SiO2 with Feldspar)
Limestone
Calcium Carbonate (CaCO3)
Amber (specifically Red or Cherry Amber)
Succinite (Resinite); Chemical formula: C10H16O
Sandstone (Quartzite Pebble)
Arenite (SiO2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Sandstone with Secondary Mineral Encrustation
Arenite with Silica/Calcite deposits (SiO2 or CaCO3)
Basalt with Caliche
Extrusive Mafic Igneous Rock with Secondary Carbonate Crust
Sandstone (likely Graywacke or Arkosic varieties)
Arenite (composed primarily of SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)