Orthoceras Fossil in Limestone
Orthoceras (extinct genus of cephalopods), mineralized as Calcite (CaCO3) in Fossiliferous Limestone
sedimentary
Category
Mineral (Biogenic Replacement)
Browse mineral (biogenic replacement) specimens identified by the Rock Identifier community.
Jasper
Microcrystalline Quartz (SiO2)
gemstone
Green Jasper / Chert
Microcrystalline Quartz (SiO2)
sedimentary
Fossil coral (likely solitary rugose coral)
Rugosa; possibly genus Heliophyllum or similar
fossil
Chert with Jasper/Quartz Inclusions
Silicon Dioxide (SiO2)
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Nodule)
Silicon Dioxide (SiO2)
sedimentary
Chert (variously known as Flint or Microcrystalline Quartz)
Silicon dioxide (SiO2)
sedimentary
Flint
Microcrystalline Quartz (SiO2)
sedimentary
Flint
SiO2 (Cryptocrystalline Quartz)
sedimentary
Calcite
Calcite (Mineral; CaCO₃)
Mineral
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood / Chalcedony (SiO2)
sedimentary
Chert Nodule
Chert (Microcrystalline Silicon Dioxide, SiO2)
sedimentary
Bivalve Fossil (Internal Mold/Steinkern)
Class Bivalvia (Fossilized Mold)
sedimentary
Fossilized Echinoid Fragment (Calycinal/Boss Fossil)
Echinodermata fossil fragment
fossil
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Jasper
Silicon dioxide (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Iron-rich breccia or weathered ironstone
Goethite–hematite-bearing limonite, possibly brecciated host rock
mineral
Pyrite
Iron Disulfide (FeS2)
Mineral
Fossilized Shark Tooth (Megalodon or Carcharocles fragment)
Elasmobranchii (Fossilized tooth root / crown section)
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Fossilized Shark Tooth
Chondrichthyes (class) fossilized tooth
fossil
Fossilized Bark
Lepidodendron / Sigillaria fossil impression
fossil
Fuchsite
Cr-bearing Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Galena-bearing sulfide ore
Galena (lead sulfide, PbS), possibly mixed with pyrite or other sulfides
mineral
Likely galena-bearing ore
Galena (lead sulfide, PbS), possibly with quartz or calcite gangue
mineral
Rhodonite
Rhodonite (Mn,Fe,Mg,Ca)SiO3
mineral
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2
mineral
Rhodonite
Manganese silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Tiger's Eye
SiO2 (Silicon Dioxide) with fibrous crocidolite inclusions
mineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
mineral
Banded Chert
Silicon Dioxide (SiO2) with impurities
sedimentary
Fossilized Bone
Permineralized Bone (Vertebrate Fossil)
fossil
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Pyrite with Galena and Sphalerite on Matrix
Iron Sulfide (FeS2), Lead Sulfide (PbS), Zinc Sulfide (ZnS)
mineral
Gastropod Fossil (Snail Stone or Steinkern)
Class Gastropoda (Calcium Carbonate - CaCO3 / Silica - SiO2 replacing original shell)
sedimentary
Fossilized shell fragment
Indeterminate fossil mollusk; likely a silicified or mineral-replaced bivalve/gastropod fragment
fossil
Tiger's Eye (Small Polished Bead)
Pseudomorph of Quartz after Crocidolite (SiO2)
mineral
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary