Ammonite Fossil (Polished Half / Cleoniceras)
Ammonoidea (Subclass), often Cleoniceras genus; fossilized with Calcite (CaCO3) and Aragonite
Sedimentary
Category
Sedimentary (Fossilized Organic Matter)
Browse sedimentary (fossilized organic matter) specimens identified by the Rock Identifier community.
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Chert Nodule in Limestone
Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
sedimentary
Fossilized Shark Tooth (Dermal Denticle or worn tooth fragment)
Elasmobranchii (fossil remains)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock
sedimentary
Petoskey Stone
Hexagonaria percarinata
fossil
Quartz-veined Limestone
Sedimentary limestone with quartz/calcite veinlets
sedimentary
Fossiliferous Limestone
Calcium Carbonate (CaCO3)
sedimentary
Fossilized Coral (Petrified Coral)
Anthozoa fossil
fossil
Petoskey Stone (Fossilized Rugose Coral)
Hexagonaria percarinata
fossil
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Fish Fossil in Limestone
Lycoptera (likely) in Micritic Limestone
sedimentary
Fossil brachiopod or bivalve shell
Likely a fossilized brachiopod; precise genus cannot be determined from the photograph
fossil
Limestone (or Sandstone)
Calcium Carbonate (CaCO3) / Silica (SiO2)
sedimentary
Gravel / Limestone Fragment
Calcium Carbonate (CaCO3) / Fine-grained Sedimentary Rock
sedimentary
Fossil Coral
Hexagonaria (or Rugose/Tabulate coral fossilized in calcium carbonate)
fossil
Dendritic Opal
Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
mineral
Ferruginous Sandstone with Concretion
Sandstone (SiO2 dominated with Fe2O3 cement)
sedimentary
Fossilized Shark Tooth (Otodus obliquus)
Otodus obliquus (Mineral composition: Bio-apatite/Calcium Phosphate replaced by various minerals)
sedimentary (fossil)
Fossilized Rugose Coral (Horn Coral)
Order Rugosa (extinct tetra-coral)
sedimentary
Fossilized Rugose Coral (Horn Coral)
Rugosa (Order) - often Grewingkia or Zaphrenthis
sedimentary
Anthracite Coal
Anthracite (Carbon Content: 86%–98%)
metamorphic
Sandstone with Brachiopod Mold Fossil
Sedimentary rock (Sandstone) with indeterminate Brachiopod mold
fossil
Banded Chert / Jasper
Silicon Dioxide (SiO2)
sedimentary
Fossilized Coral (Petoskey Stone type)
Hexagonaria percarinata (Fossilized Rugose Coral)
fossil
Fossilized Coral (Petoskey Stone type)
Hexagonaria percarinata (Fossilized Rugose Coral)
fossil
Fossiliferous Limestone
Calcite (CaCO3) matrix with biogenic fragments
sedimentary
Coral Fossil / Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
fossil
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
fossil
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
fossil
Limestone (River Pebble)
Calcium Carbonate (CaCO3)
sedimentary
Jasper
Silicon dioxide (Quartz variety), SiO2
sedimentary
Chert (often called Flint or Jasper)
Microcrystalline quartz (SiO2)
sedimentary
Chert
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Cryptocrystalline Quartz)
Silicon dioxide (SiO2)
sedimentary
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (or Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Microcrystalline silica (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (White/Gray variety)
Silicon Dioxide (SiO2 / Cryptocrystalline Quartz)
sedimentary
Chert (Flint)
Chert (SiO2)
sedimentary
Chert (Chalcedony/Common Opal)
Microcrystalline Quartz (SiO2)
sedimentary