Organic Specimen (Fossil)

Limestone

Sedimentary rock composed mainly of calcite (CaCO3)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 oxides)

Iron Ore / Hematite / Ironstone Nodule

Hematite / Goethite (Fe2O3 / FeO(OH))

Petrified Wood

Silicified Wood (SiO2 permineralization)

Petrified Wood

Silicified Wood (Permineralized organic tissue)

Amber

Succinite (organic gemstone, approx. C10H16O)

Chert (containing Fossil Inclusions)

Microcrystalline Quartz (SiO2)

Fossiliferous Chert (with Brachiopod or Mollusk fragments)

Silicon dioxide (SiO2) with Calcium Carbonate (CaCO3) inclusions

Fossil Shell (Bivalve)

Phylum Mollusca, Class Bivalvia (typically composed of Calcium Carbonate / CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Limestone with Calcite Veining

Sedimentary Carbonate Rock (CaCO3)

Fossil Shell (Bivalve)

Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3

Vivianite

Vivianite, Fe2+3(PO4)2·8H2O

Sandstone Chert Concretion

Silica-cemented Concretion (primarily SiO2)

Red Jasper with Fossils

Silicified Fossiliferous Jasper (Chert variant, SiO2)

Fossilized Shark Tooth

Carcharocles sp. or Striatolamia sp. (Phosphate/Carbonate mineralized Hydroxyapatite)

Sandstone

Arenite (SiO2 dominant)

Petrified Wood

Silicified Wood (primarily SiO2)

Sandstone

Arenite (predominantly SiO2)

Petrified Wood

Silicified wood (primarily quartz, SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Petrified Wood

Silicified Wood (SiO2)

Botryoidal Chalcedony (Quartz Var.)

Silicon Dioxide (SiO2)

Glauconitic Sandstone with possible Trace Fossil

Glauconitic Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)

Amber

Succinite (Fossilized Tree Resin)

Amber

Succinite (C10H16O)

Amber

Succinite (specifically for Baltic amber); approximate formula C10H16O

Petrified Coral Fossil (Honeycomb Coral)

Favosites (Rugosa/Tabulate coral fossil replaced by microcrystalline quartz/chalcedony)

Fossil scallop/bivalve shell

Fossilized pectinid bivalve; likely family Pectinidae (exact genus/species cannot be determined from the image)

Sandstone (Ferruginous)

Clastic Sedimentary Rock (Sandstone)

Fossiliferous Limestone with Brachiopod shell

Calcium carbonate (CaCO3)

Fossilized Fish Skeleton in Matrix

Vertebrata (Class: Actinopterygii), typically found in limestone or shale matrices

Likely fossilized shell or carbonate concretion

Indeterminate biogenic calcium carbonate, commonly calcite (CaCO₃)

Limestone

Calcium Carbonate (CaCO3)

River Pebble (Siltstone/Mudstone)

Clastic sedimentary rock

Limestone

Sedimentary Rock (Primarily CaCO3)

Petrified Wood

Silicified Wood (SiO2 permineralization)

Amber

Fossilized Tree Resin (Succinite for Baltic varieties)

Petrified Wood

Silicified Wood (Permineralized Lycopsid, Conifer, or Hardwood)