Fossilized Brachiopod
Phylum Brachiopoda (General mineral composition: Calcite/CaCO₃ or Silica/SiO₂)
Category
Browse igneous and fossil specimens identified by the Rock Identifier community.
Fossilized Brachiopod
Phylum Brachiopoda (General mineral composition: Calcite/CaCO₃ or Silica/SiO₂)
Limestone
Calcium Carbonate (CaCO3)
Chert Nodule (Commonly known as a Flint or River Cobble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sandstone (likely Calcareous or Quartz-rich)
Arenite (SiO2 based typically)
Limestone
Calcium Carbonate (CaCO3)
Red Mudstone (Siltstone)
Lutite (primarily Quartz and Clay minerals with Hematite)
Chert (Nodule)
Chert (Silicon Dioxide, SiO2)
Sandstone Cobble
Arenite (Secondary classification based on grain size)
Sandstone (Ferruginous)
Arenite (with Iron Oxide)
Limestone
CaCO3 (principally composed of Calcite)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert Nodules (Limonitic Chert)
Cryptocrystalline Quartz (SiO2) with Hydrated Iron Oxides
Ferruginous Sandstone (with Laterite)
Ferruginous Arenite (FeO(OH)·nH2O)
Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
Lignite (Brown Coal)
Humic Lignite (Carbonaceous sedimentary rock)
Sandstone Pebble
Arenite (primarily SiO2)
Sandstone (Greywacke)
Arenite / Greywacke Sandstone
Shale
Shale (clastic sedimentary rock)
Shale
Fissile mudstone (rich in clay minerals and quartz)
Fossilized Sand Tiger Shark Tooth
Carcharias taurus / Striatolamia macrota (mineralized as Hydroxylapatite/Francolite)
Chert (Banded)
Silicon Dioxide (SiO2)
Chert (potentially Fossiliferous or Jasperoid)
Microcrystalline Quartz (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Red Sandstone
Arenite (Ferruginous Sandstone)
Ferruginous Sandstone (Ironstone Nodules)
Ferruginous Sandstone with Limonite/Goethite coating (Fe2O3·H2O)
Sandstone (Ferruginous)
Arenite with Iron oxide staining (SiO2 with Fe2O3)
Sandstone
Arenite (composed primarily of SiO2)
Limestone
Calcium Carbonate (CaCO3)
Coquina
Coquina (a type of limestone)
Fossiliferous Limestone
Carbonate Rock (CaCO3 with organic inclusions)
Liesegang Ring Siltstone
Siltstone with iron oxide Liesegang bands
Sandstone
Arenite (Siliclastic sedimentary rock)
Petrified Wood
Silicified Wood (primarily SiO2)
Coquina (Fossiliferous Limestone)
Coquina (Organic Clastic Limestone)
Pyrite Sun
Iron Sulfide (FeS2)
Dendritic Agate
Silicon Dioxide with Manganese or Iron Oxide inclusions (SiO2)
Flower Agate
Chalcedony with Opaque Spherulitic Inclusions (SiO2)
Shale
Lutaceous Rock (Sedimentary Mudrock)
Chert (Nodular Chert)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
Sandstone Cobble with Liesegang Rings
Arenite with iron oxide precipitation (SiO2 matrix with Fe2O3 banding)
Shale
Fissile Siliciclastic Sedimentary Rock
Siltstone
Siltstone (primarily SiO2 with clay minerals)