Organic (Biological Specimen)

Polished fossil shell fragment (likely ammonite or bivalve)

Fossilized mollusk shell; likely aragonite/calcite replaced by silica or iron-rich minerals

Weathered fossiliferous limestone or fossil fragment

Indeterminate bioclastic carbonate rock; likely calcite (CaCO₃) with fossil shell material

Fossilized bivalve shell

Fossil Mollusca; likely a cemented or infaunal bivalve, possibly oyster or clam

Fossiliferous Limestone

Limestone (Calcium Carbonate, CaCO3)

Chert (with Quartz/Chalcedony)

Microcrystalline Quartz (SiO2)

Fossilized mammalian tooth

Mineralized dental tissue, chiefly hydroxyapatite [Ca₅(PO₄)₃(OH)]

Fossiliferous limestone

Calcite-rich carbonate rock; chiefly CaCO₃ (often bioclastic limestone)

Tree agate (dendritic agate)

Microcrystalline quartz (SiO₂) with manganese- or iron-oxide dendrites

Fossil bone fragment (likely vertebrate bone)

Fossilized vertebrate bone; exact taxon indeterminate from the photograph

Banded Jasper

Silicon Dioxide (SiO2) with impurities

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Possible fossilized tooth fragment

Indeterminate fossil enamel/dentine; possibly shark tooth fragment

Chert (Jasper/Chalcedony mix)

Microcrystalline Quartz (SiO2)

Fossiliferous limestone, possibly coral or stromatoporoid fossil

Calcitic limestone; predominantly CaCO₃, with fossilized colonial-organism structures

Bivalve Fossil (Clam)

Class Bivalvia, likely Mercenaria or similar genus

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Banded Chert (Flint)

Cryptocrystalline Quartz (SiO2)

Fossiliferous Limestone

Bioclastic Limestone (CaCO3)

Fossilized coral or stromatoporoid

Calcareous coral, likely an indeterminate fossil colonial coral (phylum Cnidaria)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with Biogenic Fossils

Silicified oyster fossil

Fossil oyster shell, commonly Ostrea or Crassostrea, replaced or encrusted by chalcedony/quartz

Fossilized coral (likely colonial coral)

Fossil scleractinian coral; possibly *Thamnasteria* or a related coral

Fossilized honeycomb coral

Fossil coral, commonly Favosites or related tabulate coral

Fossilized shell or coral fragment

Indeterminate biogenic carbonate; likely calcite/aragonite (CaCO₃)

Fossilized bivalve shell

Bivalvia indeterminate; likely a fossil clam or cockle

Fossil scallop shell

Bivalvia, likely family Pectinidae; exact species cannot be determined from the image

Fossilized bone or tooth fragment

Indeterminate fossil bone; possibly mammalian or reptilian

Fossil shark tooth

Likely fossilized shark tooth, possibly Otodus or Carcharhinus; exact identification requires a sharper, closer image

Pyrite (on host rock/ore)

Iron Sulfide (FeS2)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Fossiliferous limestone (likely stromatoporoid/coral limestone)

Calcite-rich carbonate rock, chiefly CaCO₃; visible fossil structures may be tabulate coral or stromatoporoid

Chert (Chalcedony-rich sedimentary rock)

Cryptocrystalline Quartz (SiO2)

Calcite (Yellow/Orange variety - sometimes called Honey Calcite)

Calcite

Fossiliferous limestone with brachiopod or bryozoan fossils

Calcite (CaCO₃) limestone containing marine invertebrate fossils, possibly brachiopoda or bryozoa

Firewood (Wood Log)

Lignum (Plant tissue composed of cellulose and lignin)

Chert

Microcrystalline Quartz (SiO2)

Polished fossiliferous limestone

Bioclastic limestone, likely containing a solitary rugose coral or shell fossil (identification uncertain from image)

Crinoid and Coral Fossils in Limestone

Fossiliferous Limestone with Rugosa (order) and Crinoidea (class)

Shell Cameo

Cypraecassis rufa (Bullmouth Queen Helmet Shell)

Pyrite

Iron Disulfide (FeS2)

Leopard-skin jasper (likely orbicular jasper)

Silicified volcanic rock, primarily microcrystalline quartz (SiO₂) with iron-oxide and dark mineral inclusions