Organic Specimen (Fossil)

Fossil Rugose Coral (Horn Coral)

Order Rugosa

Sandstone (Quartzose Sandstone)

Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 staining)

Sandstone

Arenite (primarily SiO2)

Tumbled tree agate (dendritic agate)

Cryptocrystalline quartz, SiO₂, with manganese/iron-oxide dendrites

Sandstone (Ferruginous)

Arenite (Fe-rich)

Sandstone with trace fossil

Sandstone, possibly with Skolithos or similar trace fossil

Weathered limestone

Calcite-rich carbonate rock (mostly CaCO₃), possibly fossiliferous limestone

Chert (Chert Nodule with Cortex)

Microcrystalline Quartz (SiO2)

Weathered fossiliferous limestone fragment, possibly fossil coral or shell material

Indeterminate carbonate fossil in calcitic limestone; likely composed mainly of calcite (CaCO₃), but species identification is not possible from this image alone

Sandstone (Banded)

Arenite

Chert (Nodule)

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

Weathered quartz-rich cobble, possibly quartzite or feldspar-rich granite

Quartz–feldspar aggregate; identification is uncertain from the photograph

Sandstone (River Rock)

Arenite (SiO2 principal component)

Fossiliferous Limestone (Coquina / Shell Limestone)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Petrified Wood

Silicified Wood (primarily quartz/chalcedony replacing organic wood structures, SiO2)

Chert (with inclusions)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone (Muddy/Silty Variety)

Arenite with high silt/clay content (clastic sedimentary rock)

Fossilized shell fragment

Indeterminate fossil mollusk; likely a silicified or mineral-replaced bivalve/gastropod fragment

Coral Rock (Coquina)

Biogenic Limestone (Calcium Carbonate - CaCO3)

Sandstone (Ferruginous)

Arenite (with Goethite/Limonite cement)

Sandstone (likely Fossilized Wood or Concrete Simulacrum)

Arenite / Silicified Wood / Anthropogenic Concrete

Travertine (Tufa)

Chemical Limestone (CaCO3)

Fossiliferous Limestone with Brachiopod Mold

Calcium Carbonate (CaCO3) matrix containing Brachiopoda fossil impressions

Fossiliferous Limestone (Chertified Limestone)

Calcium Carbonate (CaCO3) often replaced by Microcrystalline Silica (SiO2)

Sandstone (Quartzose Sandstone)

Arenite (SiO2 primarily)

Red Sandstone with Reduction Spot

Quartzose Sandstone with a Leach/Reduction Spot

Fossilized Shark Tooth

Fossilized elasmobranch tooth (Apatite/Calcium Phosphate)

Echinoidea (Fossil Sea Urchin)

Echinodermata Echinoidea

Chert (specifically Yellow/Brown Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone (River Stone)

Arenite (primarily SiO2)

Chert (and Fossiliferous Chert)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Sandstone with Vitrinite/Coal inclusions

Arenite with Carbonaceous inclusions

Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

Sandstone

Arenite (composed primarily of SiO2)

Handaxe with Inlaid Fossil Echinoid

Flint / Chert (SiO2) containing a fossil Conulus albogalerus

Weathered limestone or calcareous sandstone

Likely micritic limestone (calcite, CaCO₃), possibly carbonate-rich sandstone

Sandstone (Stream-rounded)

Arenite (SiO2 based)

Petrified Wood

Silicified Wood (primarily SiO2)

Crushed Limestone

Calcite-rich Sedimentary Rock (CaCO3)

Polished petrified wood

Silicified wood, primarily microcrystalline quartz (SiO₂) replacing organic tissue