Fossil Coral
Cnidaria Anthozoa (Fossilized)
Category
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
Fossil Coral
Cnidaria Anthozoa (Fossilized)
Chalcedony (Grey/White Agate)
Silicon Dioxide (SiO₂)
Rhodonite
Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3
Carnelian (Red Chalcedony)
Silicon Dioxide (SiO2) with iron oxide impurities
Yellow Jasper
Tectosilicates (SiO2) with Goethite/Iron oxide inclusions
Jasper
Silicon dioxide (SiO2) with impurities
Pyrite
Iron Sulfide (FeS2)
Hematite with Magnetite
Iron Oxide (Fe2O3)
Pyrite (Cube variety)
Iron Sulfide (FeS2)
Chert (Flint)
Chert (predominantly SiO₂ - silicon dioxide)
Chalcedony
Cryptocrystalline Quartz (SiO2)
Chert (Flint) with Glauconite
Microcrystalline Quartz (SiO2)
Ferruginous Sandstone (Gozzanous)
SiO2 (Quartz) with FeO(OH) (Goethite) or Fe2O3 (Hematite) coating
Bivalve Fossil (Internal Mold/Steinkern)
Class Bivalvia (Fossilized Mold)
Magnetite / Hematite mix (Iron Ore)
Fe3O4 (Magnetite) / Fe2O3 (Hematite)
Gastropod Fossil (Snail Internal Mold)
Gastropoda; internal mold (steinkern), often composed of Calcium Carbonate (CaCO3) or Silica (SiO2)
Jasper
Silicon Dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Celestine (Celestite)
Strontium Sulfate (SrSO4)
Fossilized Sand Tiger Shark Tooth
Carcharias taurus / Striatolamia macrota (mineralized as Hydroxylapatite/Francolite)
Green Jasper
Jasper (Silicon Dioxide, SiO2)
Chert / Flint
Chert (varieties include Flint)
Chert (White Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossilized Megalodon Tooth Fragment
Otodus megalodon (Carcharocles megalodon fossil)
Red Jasper (Tumbled)
Silicon Dioxide (SiO2) with iron oxide inclusions
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Magnetite
Magnetite (Fe3O4)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Coprolite
Fossilized feces (various taxa)
Chert (Tripolitic Chert / Flint Nodules)
Microcrystalline Quartz (SiO2)
Chert (with Limestone and Iron Oxide staining)
Cryptocrystalline Quartz (SiO2)
Chert (Common Opal/Agate inclusion)
Microcrystalline Quartz (SiO2)
Calamites (Fossilized Horsetail)
Calamites suckowii (Family: Calamitaceae)
Carnelian
Carnelian (SiO2 with Iron Oxide impurities)
Pyrite
Iron Disulfide (FeS2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Ironstone Concretion
Siderite or Hematite Concretion
Orthoceras Fossil in Limestone
Orthoceras (extinct genus of cephalopods), mineralized as Calcite (CaCO3) in Fossiliferous Limestone
Fossilized Coral (Petoskey Stone or Rugose Coral)
Antophyllum (Hexagonaria) or Scleractinia (CaCO3)
Chert (Flint variety)
Chert (Cryptocrystalline variety of Quartz, SiO2)
Chert (Jasper/Carnelian variety)
Microcrystalline Quartz (SiO2)
Jasper
Silicon dioxide (SiO2)