Limonite (Ironstone)
Limonite (FeO(OH)·nH2O)
Category
Browse sedimentary (biogenic) specimens identified by the Rock Identifier community.
Limonite (Ironstone)
Limonite (FeO(OH)·nH2O)
Chert (and Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Basalt River Stone
Basalt
Yellow Quartzite (Onyx Pebble)
Silicon Dioxide (SiO2) - Quartzite
Chert (often called Flint in dark varieties)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Banded Sandstone
Arenite with Liesegang banding (primarily SiO2 with FeO(OH) impurities)
Chert (Iron-stained)
Chert (Cryptocrystalline Silica, SiO2)
Quartz Druzy (Geode Fragment)
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Sandstone
Arenite
Sandstone
Arenite (SiO2 based)
Megalodon Shark Tooth Fossil
Otodus megalodon
Siltstone / Fine-grained Graywacke
Argillaceous siltstone
Siltstone
Siltstone (primarily SiO2 with Al2O3)
Chert (Flint)
Silicon Dioxide (SiO2)
Quartz (likely milky/rose quartz variety)
Quartz (SiO2 - Silicon Dioxide)
Ironstone
Ferruginous Sedimentary Rock (composed of Goethite, Hematite, and Limonite)
Red Sandstone (Iron-stained)
Clastic sedimentary rock (primarily Quartz with Iron Oxides)
Quartz Veinated Sandstone or Siltstone
Silicon Dioxide (SiO2) within a clastic sedimentary matrix
Sandstone (Ferruginous)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)
Concretionary Sandstone
Clastic Sedimentary Rock (Sandstone with secondary mineral cementation)
Sandstone (likely Siltstone or Mudstone variety)
Clastic Sedimentary Rock (primarily SiO2 with iron oxides)
Quartz-veined Siltstone/Greywacke
Clastic Sedimentary Rock with Quartz Infill (SiO2 vein)
River Pebbles (White Quartz and Basalt mix)
Mixed Clastic Sedimentary Assemblage (SiO2 and Mafic Volcanics)
Chert (includes Flint & Jasper)
Chert (Siliceous sedimentary rock, chemical formula SiO2)
Chert Conglomerate (or Breccia)
Sedimentary Clastic Rock (variety: Ferruginous Chert Breccia)
Limestone with Chert or Siltstone bands
Sedimentary carbonate rock (CaCO3) often with siliceous impurities
Grey River Pebble (Likely Quartz-rich or Limestone)
Clastic Sedimentary Rock (typically SiO2 or CaCO3 based)
Fossiliferous Shale Matrix
Clastic Sedimentary Rock with Brachiopod or Mollusk shell fragments
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 oxides)
Ferruginous Conglomerate (or Iron-Rich Concrete/Slag)
Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)
Quartz Geode in Chert/Limestone Matrix
Silicon Dioxide (SiO2) within Sedimentary Host Rock
Sandstone
Clastic Sedimentary Rock (composed primarily of Quartz: SiO2)
Sandstone Concretion with Quartz Center
Sedimentary Clastic Rock (SiO2 matrix with Quartz core)
Chert Pebble/Nodule
Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 staining)
Sandstone Concretion
Clastic Sedimentary Rock (primarily SiO2 with mineral cement)
Milky Quartz in Conglomerate Matrix
Silicon Dioxide (SiO2) within Clastic Sedimentary Rock
Limestone
Sedimentary rock composed primarily of Calcium Carbonate (CaCO3)