Chert (Flint)
Chert (SiO2)
sedimentary
Category
Igneous And Fossil
Browse igneous and fossil specimens identified by the Rock Identifier community.
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Siltstone Pebble
Siltstone (composed of microscopic quartz and clay minerals)
sedimentary
Red Sandstone
Clastic sedimentary rock (primarily SiO2 with Fe2O3)
sedimentary
Chert (Nodular or Fossiliferous)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (and Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Iron-stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone
Arenite
sedimentary
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Iridescent Ammonite Fossil
Ammonoidea (subclass); Composition: Aragonite (Calcium Carbonate, CaCO3) often replaced by Calcite or Pyrite
sedimentary
Brachiopod Fossil (Spiriferid)
Order Spiriferida (Phylum Brachiopoda); mineralized as Calcite (CaCO3) or Chert (SiO2)
sedimentary (fossilized organic remain)
Coral Fossil (Petrified Coral)
Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)
sedimentary
Fossilized Bone Fragment
Permineralized Vertebrate Fossil (Hydroxyapatite replaced by Minerals)
sedimentary
Fossilized Shark Tooth (Fragment)
Elasmobranchii fossil (likely Cretalamna or Squalicorax genus)
sedimentary
Pyrite in Shale
Iron Disulfide (FeS2) in Argillaceous Shale
sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Crinoid Stem Fragment
Crinoid (Phylum Echinodermata, Class Crinoidea)
sedimentary
Sandstone
Arenite (SiO2 primarily)
sedimentary
Mixed Mineral and Fossil Collection
Multi-specimen assemblage (SiO2, CaCO3, FeS2, etc.)
mineral
Favosites (Fossil Coral)
Favosites (Extinct Tabulate Coral)
sedimentary
Crinoid Fossil Limestone
Crinoidal Limestone (Calcite / CaCO3)
sedimentary
Spinosaurus Tooth Fossil
Spinosaurus aegyptiacus (Calcium Phosphate/Apatite)
sedimentary
Belemnite Fossil (Guard)
Belemnoidea (Carbonate/Calcite replacement)
sedimentary
Gastropod Fossil (Snail)
Gastropoda (Internal mold/Steinkern)
sedimentary
Rugose Coral Fossil
Rugosa (Order)
sedimentary
Fossil Bivalve Shell
Class Bivalvia (e.g., Veneriidae family)
sedimentary
Bivalve Fossil (Clam)
Class Bivalvia (Calcium Carbonate, CaCO3)
sedimentary
Fossil Shell (Bivalve)
Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3
sedimentary
Brain Coral Fossil
Family Mussidae or Merulinidae (Order Scleractinia)
sedimentary
Crinoid Fossil in Limestone
Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)
sedimentary
Fossil Shark Tooth
Carcharocles (Otodus) sp. or similar fossilized Chondrichthyes tooth
sedimentary
Crinoid Fossil in Chert
Crinoid (Class Crinoidea) in Microcrystalline Quartz (SiO2)
sedimentary
Calamites (Fossil Plant)
Calamites (Genus), belonging to the class Equisetopsida
sedimentary
Honeycomb Coral Fossil
Favosites (extinct genus of tabulate coral)
sedimentary
Horn Coral Fossil
Rugosa (extinct order of solitary corals)
sedimentary
Limestone or Chalk
Calcium Carbonate (CaCO3)
sedimentary
Red Jasper with Fossils
Silicified Fossiliferous Jasper (Chert variant, SiO2)
sedimentary
Sandstone (Quartzose Sandstone)
Arenite (primarily SiO2)
sedimentary
Quartzite Pebble (with possible inclusion)
Metamorphosed Quartz Sandstone (SiO2 with impurities)
metamorphic
Black Limestone with Calcite Veining
Bituminous Limestone (CaCO3 with Organic Carbon inclusions)
sedimentary
Chert Concretion
Microcrystalline Quartz (SiO2) in Carbonate Matrix
sedimentary
Sandstone
Arenite (SiO2 predominantly)
sedimentary
Sandstone
Arenite
sedimentary