Chert (Nodular)
Cryptocrystalline Quartz (SiO2)
Category
Browse fossil specimens identified by the Rock Identifier community.
Chert (Nodular)
Cryptocrystalline Quartz (SiO2)
Sandstone
Arenite
Chert (Brown Flint)
Cryptocrystalline or Microcrystalline Quartz (SiO2)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Dendritic Agate (also known as Dendritic Siltstone or Mudstone)
Silicon Dioxide with Manganese/Iron Oxide inclusions (SiO2 + MnO2)
Sandstone Concretion
Arenaceous concretion (primarily SiO2 with Fe2O3 staining)
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Petrified Wood
Silicified Wood (primarily SiO2)
Amber
Organic gemstone (Succinite is common if from the Baltic)
Sandstone
Arenite
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Glauconitic Sandstone
Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2 in Quartz Sandstone
Petrified Wood
Silicified Wood (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Concretion
Septarian concretion (likely containing Calcite or Siderite)
Limestone Pebble
Sedimentary Calcium Carbonate (CaCO3)
Shale (possibly Carbonaceous or Oil Shale)
Argillaceous Sedimentary Rock
Sandstone
Arenite (SiO2 based with quartz, feldspar, or lithic fragments)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement (SiO2 + Fe2O3)
Sandstone (Quartzose)
Arenite (SiO2 based)
Sandstone
Arenite (SiO2 with Fe2O3)
Chert (River Pebble)
Chert (Microcrystalline Silicon Dioxide, SiO2)
Sandstone (likely Arkosic or Lithic)
Clastic Sedimentary Rock (composed mostly of SiO2)
Coquina
Coquina Limestone (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Sandstone (Red/Ferruginous)
Arenite (with iron oxide cement)
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement
Limestone
Calcium Carbonate (CaCO3)
Limestone
Sedimentary rock composed of Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Sandstone (with Lichen)
Arenite (primarily SiO2)
Fossilized Coral (Favosites)
Favosites goldfussi / Tabulata
Chert (Flint)
Silicon Dioxide (SiO2)
Limestone
Calcium carbonate (CaCO3)
Sandstone
Arenite
Chert (Limonite-stained)
Microcrystalline Quartz (SiO2) with iron oxides
Limestone with Chert or Siltstone bands
Sedimentary carbonate rock (CaCO3) often with siliceous impurities
Shale (or Mudstone)
Siltstone/Argillite (composed mainly of clay and silt-sized particles)
Sandstone (likely Fossiliferous Sandstone)
Clastic sedimentary rock (primarily SiO2)
Limestone
Calcium Carbonate (CaCO3)
Chert (Nodule)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz