Shale (sub-type: Carbonaceous Shale)
Lutaceous Sedimentary Rock
sedimentary
Category
Organic Specimen (Fossil)
Browse organic specimen (fossil) specimens identified by the Rock Identifier community.
Learn about Organic Specimen (Fossil) in the encyclopedia
View all →
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Sandstone
Arenite (SiO2 based)
sedimentary
Limestone
Sedimentary rock composed mainly of calcium carbonate (CaCO3)
sedimentary
Chert (variably Oolitic or Fossiliferous)
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone (with Iron Staining)
Clastic sedimentary rock (SiO2 with Fe2O3 impurities)
sedimentary
Coquina
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Crinozoan fossil (Crinoid stem fragment)
Crinoid (Class Crinoidea)
fossil
Limestone Pebble
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Fossil shell fragment
Likely a fossilized brachiopod or bivalve; exact taxon cannot be determined from the image
fossil
Coquina or Coral Fossil
Biogenic Limestone (Calcite/Aragonite)
sedimentary
Grass (Organic Matter/Soil)
Poaceae (family of monocotyledonous flowering plants)
Organic Materia (Not a rock or mineral)
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Fossilized Bone Fragment
Permineralized Vertebrate Fossil (Hydroxyapatite replaced by Minerals)
sedimentary
Fossilized Shark Tooth
Fossilised Chondrichthyes dental specimen (likely Otodus or Carcharias sp.)
mineral
Septarian Nodule
Septarian Concretion (Calcite, Aragonite, and Limestone)
sedimentary
Sandstone (Greywacke)
Arenite / Wacke (SiO2 + varied clasts)
sedimentary
Sandstone (Quartzose Sandstone)
Clastic sedimentary rock (SiO2 primary composition)
sedimentary
Concretionary limestone or calcarenite pebble
Micritic limestone/calcarenite, primarily calcite (CaCO₃)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO₂)
sedimentary
Glauconitic Sandstone (Greensand pebble)
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
sedimentary
Fossilized Sea Urchin (Echinoid)
Echinoidea (Fossil specimen, often replaced by Calcite or Silica)
sedimentary
Chert (Nodule)
Silicon Dioxide (SiO2)
sedimentary
Sandstone (Quartz Arenite)
Sandstone (SiO2 with possible mineral cements)
sedimentary
Ironstone (Limonite/Hematite concretion)
Ferruginous Siltstone / Goethite (FeO(OH))
sedimentary
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 oxides)
sedimentary
Pyrite in Shale
Iron Disulfide (FeS2) in Argillaceous Shale
sedimentary
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Limestone with Fossil Fragment
Bioclastic limestone (Calcium carbonate, CaCO3)
sedimentary
Ironstone Concretion
Goethite-rich Siltstone / Siderite (FeCO3)
sedimentary
Fossil brachiopod or bivalve shell
Likely a fossilized brachiopod; precise genus cannot be determined from the photograph
fossil
Fossilized cylindrical shell or bone fragment
Indeterminate biogenic carbonate or phosphatic fossil; possible fragment of a tubular shell (e.g., scaphopod) or hollow bone
fossil
Fossilized oyster shell in limestone
Bivalvia fossil; chiefly calcite (CaCO₃)
fossil
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Likely weathered quartz-rich stone or fossil fragment
Indeterminate; possibly quartz-bearing sandstone, iron-stained quartz, or a fragmentary fossil
mineral
Sandstone
Arenite (primarily SiO2)
sedimentary
Banded Chert / Agate
Silicon Dioxide (SiO2)
sedimentary
Agate (or Operculum / Fossil Shell)
Silicon Dioxide (SiO2)
mineral
Fossilized Shark Tooth (Cretaceous to Neogene)
Elasmobranchii dental fossil (likely Squalicorax or similar species)
mineral (biogenic replacement)
Fossiliferous Chert with Brachiopod Impression
Chert (SiO2) containing Brachiopoda fossil remains
sedimentary
Hag Stone
Perforated Flint or Chert
sedimentary