Fossilized Bivalve Shell
Bivalvia (fossil specimen)
Category
Browse sedimentary (biogenic sediment or biological remain) specimens identified by the Rock Identifier community.
Fossilized Bivalve Shell
Bivalvia (fossil specimen)
Banded Chert
Microcrystalline Quartz (SiO2)
Sandstone Concretion
Arenaceous concretion (primarily SiO2 with Fe2O3 staining)
Bivalve Fossil (Internal Mold/Steinkern)
Class Bivalvia (Fossilized Mold)
Fossilized Brachiopod
Phylum Brachiopoda (General mineral composition: Calcite/CaCO₃ or Silica/SiO₂)
Cockle Shell (Fossil or Recent)
Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)
Shale
Fissile mudrock (composed of clay-sized particles and detrital grains)
Jasper
Silicon dioxide (SiO2)
Tufa
Calcareous Tufa (CaCO3)
Pyrite in Matrix (Fool's Gold)
Iron Sulfide (FeS2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Fossil Shark Tooth (embedded in matrix)
Lamniformes (likely Cretalamna or Squalicorax) within phosphatic/calcareous matrix
Jasper (Green variety)
Silicon Dioxide (SiO₂)
Sandstone Concretion
Sandstone (Sedimentary Rock) with silica or calcite cement
Amber
Succinite (specifically for Baltic amber; general formula C10H16O)
Calcite (Yellow/Orange variety - sometimes called Honey Calcite)
Calcite
Chert (variations include Flint or Jasper)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Desert Varnish (on Sandstone)
Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)
Howlite (White Buffalo Turquoise)
Howlite (Calcium Borosilicate Hydroxide), Ca2B5SiO9(OH)5
Fossilized Shark Tooth
Fossilized Elasmobranchii tooth (likely Odontaspis or Carcharias)
Chert / Flint (with Iron Staining)
Silicon Dioxide (SiO2)
Fossiliferous Brachiopod in Shale
Brachiopoda (Phylum) preserved in Carbonaceous Shale
Sandstone Concretion
Sedimentary Concretion (SiO2 or CaCO3 cemented)
Fossilized Crinoid Stem Segment
Crinoid (Phylum Echinodermata, Class Crinoidea)
Sandstone (Ferruginous)
Arenite with Iron oxide staining (SiO2 with Fe2O3)
Conglomerate
Conglomerate (SiO2 matrix with various inclusions)
Red Jasper
Jasper (SiO2) - Silicon Dioxide with Hematic impurities
Ironstone Concretion
Siderite or Limonite Concretion
Ironstone Concretion
Siderite or Hematite-bonded Concretion
Jasper
Silicon dioxide (SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) - variety Jasper
Siltstone/Sandstone (possibly Wonderstone or Picture Sandstone)
Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide inclusions)
Conglomerate with Quartz Inclusions
Conglomerate (clastic sedimentary rock) with internal Quartz (SiO2)
Amber
Succinicum (Succinite); C10H16O
Ironstone Concretion / Limonite-stained Siltstone
Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)
Ammonite Fossil
Ammonoidea (subclass)
Gastropod Fossil (Snail Steinkern)
Class Gastropoda fossil, composed of Calcium Carbonate (CaCO3)
Shale
Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)
Jasper
Jasper (Silicon Dioxide, SiO2)
Ironstone Concretion
Siderite or Ferruginous Concretion (FeCO3 or Iron Oxides)
Amber
Succinicum (C10H16O)
Brachiopod Fossil in Chert
Phylum Brachiopoda within Microcrystalline Quartz (SiO2)