Fossilized Wood (Petrified Wood)
Silicified Wood (primarily quartz/chalcedony replacing organic matter)
Category
Browse fossil specimens identified by the Rock Identifier community.
Fossilized Wood (Petrified Wood)
Silicified Wood (primarily quartz/chalcedony replacing organic matter)
Slate
Slate (foliated metamorphic rock rich in quartz, sericite, and chlorite)
Sandstone (likely Quartzose Sandstone)
Arenite (primarily SiO2)
Grey Limestone Pebble
Limestone (Calcium Carbonate - CaCO3)
Sandstone (Quartz-rich)
Arenite (composed primarily of SiO2)
Sandstone (Quartz-rich)
Arenite (SiO2 based clastic rock)
Limestone (Brecciated/Recrystallized)
Calcium Carbonate (CaCO3)
Favosites (Honeycomb Coral Fossil)
Favosites sp. (Phylum Cnidaria, Order Tabulata)
Petoskey Stone (Coral Fossil)
Hexagonaria percarinata (Fossilized colonial rugose coral)
Calamites Fossil (Horsetail Stem)
Calamites (Genus), part of the class Equisetopsida
Sandstone Concretion
Septarian or Carbonate-cemented Sandstone Concretion
Ironstone Concretion (likely)
Goethite/Hematite/Limonite cemented sediment
Limestone
Calcium Carbonate (CaCO3)
Marble
Recrystallized Calcite (CaCO3)
Amber
Succinite (fossilized tree resin)
Amber
Succinite (Resin C10H16O)
Amber
Succinite (Fossilized Tree Resin)
Amber
Succinite (with approximate formula C10H16O)
Chert Pebble / Brachiopod Fossil Internal Mold
Silicon Dioxide (SiO2) / Fossil: Brachiopoda (generic internal mold)
Chert (with Manganese Dendrites)
Chert (Cryptocrystalline Quartz, SiO2)
Shale
Argillaceous Rock
Chert (Nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Limestone (River Pebble)
Sedimentary Calcium Carbonate (CaCO3)
Boxwork Siderite or Sepatarian Nodule Weathering
Siderite (FeCO3) with secondary mineralization or Boxwork Geode fragment
Stromatolite
Biogenic Sedimentary Rock (Lithified microbial mat)
Pyrite
Iron Sulfide (FeS2)
Fossil Shark Tooth (embedded in matrix)
Lamniformes (likely Cretalamna or Squalicorax) within phosphatic/calcareous matrix
Sandstone
Sandstone (clastic sedimentary rock), primarily SiO2
Granitic Gneiss
Gneiss (Polymetamorphic Granitic Gneiss)
Sandstone
Arenite (composed primarily of Quartz: SiO2)
Ironstone Concretion (Iron-rich Mudstone)
Siderite / Geothite concretion (FeCO3 / FeO(OH))
Limestone (specifically Grainstone or Micrite)
Calcium Carbonate (CaCO3)
Siltstone
Siltstone (primarily composed of SiO2, Al2O3, and phyllosilicates)
Glauconitic Sandstone (Greensand)
Glauconitic quartz wacke or arenite
Sandstone Chert Concretion
Silica-cemented Concretion (primarily SiO2)
Limestone
Calcium Carbonate (CaCO3)
Fossilized Stingray Mouth Plate
Myliobatidae dental battery
Ferruginous Sandstone (Gozzanous)
SiO2 (Quartz) with FeO(OH) (Goethite) or Fe2O3 (Hematite) coating
Ironstone (with Limonite/Goethite)
Ferruginous Sedimentary Rock (contains Limonite FeO(OH)·nH2O and Hematite Fe2O3)
Asphalt (Bituminous pavement)
Bituminous concrete / Asphalt
Oolitic Chert
Silicon Dioxide (SiO2) with oolitic texture
Chert (often called Flint)
Microcrystalline Quartz (SiO2)