Reddish Brown Claystone or Siltstone
Argillite / Siltstone / Claystone
sedimentary
Category
Sedimentary (Fossil)
Browse sedimentary (fossil) specimens identified by the Rock Identifier community.
Ferruginous Sandstone (with possible trace fossils)
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)
sedimentary
Flower Jasper
Agatized Fossil Coral / Chalcedony (SiO2)
sedimentary
Crinoid Stem Columns (Fossil)
Crinoidea (Class); often composed of the mineral Calcite (CaCO3)
sedimentary
Septarian Nodule (Dragon Stone)
Septarian concretion (CaCO3 with Aragonite and Calcite)
sedimentary
Agatized Fossil (Druzy Agate)
Silicon Dioxide (SiO2) replacing organic matter
sedimentary
Red Sandstone
Clastic sedimentary rock (primarily SiO2 with Fe2O3)
sedimentary
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Fossiliferous Limestone with Brachiopod Mold
Calcium Carbonate (CaCO3) matrix containing Brachiopoda fossil impressions
sedimentary
Larimar and Fossil Coral
Pectolite (NaCa2Si3O8(OH)) and Hexagonaria/Petoskey Stone
mineral and sedimentary
Limestone (Porous/Travertine variant)
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Fossiliferous Shale (with Vertebrate Bones)
Laminated Mudstone containing Fossilized Bone (Apatite)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Chert (specifically a flint nodule component)
Microcrystalline quartz (SiO2)
sedimentary
Coquina
Coquina Limestone
sedimentary
Turritella (Gastropod Fossil)
Turritella (Genus of gastropods), CaCO3 (Calcium Carbonate or Silicified Agate)
sedimentary
Sandstone (Stream-rounded)
Arenite (SiO2 based)
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Ironstone Concretion (Limonite/Goethite)
Iron oxide concretion (contains FeO(OH)·nH2O)
sedimentary
Sandstone (likely Quartzose Sandstone with mineral staining)
Arenite (composed mainly of SiO2)
sedimentary
Sandstone
Arenite (primarily SiO2 with trace Fe2O3)
sedimentary
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with varying levels of hydration
mineral
Fossiliferous Limestone (Crinoidal)
Calcium Carbonate (CaCO3) - Limestone containing bioclasts
sedimentary
Fossil Coral (Honeycomb Coral)
Favosites (extinct genus of Tabulate coral)
sedimentary
Fossiliferous Limestone (Coquina / Shell Bed)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Calcareous biomicrite / Bioclastic limestone
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone (Quartz-rich Pebble)
Arenite (primarily SiO2)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Conglomerate
Conglomerative Sedimentary Rock
sedimentary
Shale
Shale (composition varies: primarily clay minerals and quartz)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Shale with Siltstone layering
Sedimentary Clastic Rock (Mudstone/Shale)
sedimentary
Manganese Oxide Crust on Limestone
Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3
sedimentary
Sandstone
Arenite (Sedimentary Rock)
sedimentary
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
sedimentary
Iridescent Ammonite
Ammonoidea (Species: likely Cleoniceras or Desmoceras); Mineral: Aragonite/Ammolite (CaCO3)
sedimentary (fossilized)
Sandstone
Clastic Sedimentary Rock (composed mostly of SiO2)
sedimentary
Chert (Nodular or Fossiliferous)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary