Common Opal / Chert
Hydrated silica (SiO2·nH2O) or Microcrystalline Quartz (SiO2)
Category
Browse sedimentary (man made composite) specimens identified by the Rock Identifier community.
Common Opal / Chert
Hydrated silica (SiO2·nH2O) or Microcrystalline Quartz (SiO2)
Sandstone
Sandstone (Silicon dioxide, SiO2 based)
Sandstone
Arenite (SiO2 based typically)
Sandstone (Quartzose Sandstone)
Arenite (SiO2 principal component)
Sandstone
Arenite (SiO2 primarily)
Sandstone
Arenite (SiO2 based)
Sandstone (specifically Arkose or Ferruginous Sandstone)
Sandstone (SiO2 predominant)
Glauconitic Sandstone
Glauconitic Sandstone (Quartz with Glauconite)
Fossil Sponge / Horn Coral / Crinoid Stem
Phylum Porifera or Cnidaria fossilized in calcium carbonate / silica
Banded Chert
Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)
Limestone (specifically Dolomitic/Crystalline Limestone)
Sedimentary Carbonate Rock (CaCO3 / CaMg(CO3)2)
Jasper, Agate, Quartz Mix (Polished Beads)
SiO₂ (Silicon Dioxide) for Quartz. Jasper and Agate are cryptocrystalline varieties of Quartz.
Chert (Sedimentary Rock)
Silicon Dioxide (SiO2)
Limestone with Fossil Fragments
Bioclastic Limestone (CaCO3)
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Sandstone (likely Graywacke or Lithic Arenite)
Clastic sedimentary rock predominantly composed of silicate grains
Sandstone/Quartzite
Sedimentary Rock (composed mainly of SiO2)
Limestone (River Stone)
Calcium Carbonate (CaCO3)
Sandstone
Arenite (primarily SiO2)
Sandstone with Iron Staining
Arenite (SiO2 with FeO(OH) impurities)
Limestone (with possible Manganese oxide inclusions)
Sedimentary Calcium Carbonate (CaCO3)
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2)
Limestone (specifically a Crushed Aggregate fragment)
Calcium Carbonate (CaCO3)
Sandstone (lithic wacke/arenite)
Clastic sedimentary rock (primarily SiO2)
Sandstone
Arenite (SiO2 based)
Limestone
Calcium Carbonate (CaCO3)
Sandstone (likely Graywacke or Arkose variant)
Clastic Sedimentary Rock (SiO2 based)
Sandstone
Arenite (SiO2 primarily)
Sandstone
Arenite (primarily SiO2)
Rounded river cobble, likely weathered sandstone or siltstone
Quartz-rich clastic sedimentary rock; exact identification requires a fresh surface and testing
Shale
Shale (Lutite)
Sandstone
Arenite (SiO2 based with various mineral cements)
Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3/FeO(OH) cement)
Red Sandstone
Arenite (SiO2 with Fe2O3)
Sandstone (Red Arkose)
Sandstone (Arkose variant, primarily SiO2 with KAlSi3O8)
Sandstone (with Siltstone/Greywacke variations)
Sedimentary Rock (Clastic)
Hematitic Sandstone
Sandstone with Hematite inclusions (SiO2 + Fe2O3)
Quartzite Conglomerate
Conglomerate (SiO2 rich)
Red Jasper (or Agate/Jasper mixture)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Chert (Agatized/Chalcedony variety)
Microcrystalline Quartz (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)