Mineralized Fossil

Petrified Wood

Silicified Wood (SiO2)

Polished granite countertop with fossil shell

Granite; shell likely a fossilized bivalve or gastropod

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Fossilized bone fragment (probable mammal bone)

Mineralized bone; taxonomic identification requires microscopy and preparation

Fossil shark teeth

Likely fossilized shark teeth, possibly Carcharhiniformes or related sharks; exact species cannot be determined from the photo.

Fossilized shell or bone fragment

Indeterminate biogenic calcite or apatite fossil

Fossil-bearing sedimentary rock, possibly fossil wood or bone

Indeterminate silicified/carbonate fossil in sandstone or mudstone

Likely fossilized bone or tooth fragment

Indeterminate fossil bone; mineral replacement commonly calcite, silica, or iron oxides

Brachiopod Fossil in Matrix

Phylum Brachiopoda

Fossilized shell or coral fragment

Indeterminate calcareous fossil; likely aragonite/calcite (CaCO₃)

Fossilized tooth fragment, possibly a mammalian tooth

Indeterminate fossil tooth; enamel and dentine, taxon not identifiable from this fragment

Slate with Fossiliferous Impressions

Metamorphosed Argillaceous Rock (Fossiliferous Slate)

Fossilized bone fragment (probable large mammal bone)

Mineralized vertebrate bone; commonly hydroxyapatite, Ca₅(PO₄)₃(OH), partly replaced by silica or calcite

Polished fossil coral

Fossilized colonial coral, commonly Hexagonaria (Petoskey stone) or related rugose/tabulate coral

Fossil tooth, likely shark tooth

Likely fossilized shark tooth (possibly a small lamniform shark; exact taxon cannot be confirmed from the image)

Petrified wood

Silicified fossil wood, primarily quartz (SiO₂) replacing cellulose

Fossilized bivalve or brachiopod shell

Indeterminate calcitic shell fossil; likely Bivalvia or Brachiopoda

Fossilized tooth, likely a mammalian tooth fragment

Indeterminate fossil tooth; possibly an ungulate or carnivoran tooth

Fossil sea urchin (echinoid)

Fossilized echinoid test, likely a regular sea urchin (Class Echinoidea); exact genus and age require locality and examination

Fossil brachiopod or bivalve shell

Indeterminate fossilized carbonate shell; likely a brachiopod (Phylum Brachiopoda)

Fossil bivalve shell, likely oyster or related mollusk

Fossilized oyster-like bivalve; exact genus and age cannot be determined from the photograph

Fossilized ammonite

Ammonoidea (likely a small, chambered ammonite fossil)

Agatized fossil clam/bivalve specimens

Fossil bivalve shells, partly replaced or infilled by chalcedony and quartz (SiO₂)

Fossilized tooth, likely a shark tooth

Fossil vertebrate tooth; exact taxon uncertain, possibly Otodus/Carcharodon-type

Fossilized tooth, likely mammoth or mastodon molar fragment

Proboscidean molar enamel and dentin; Mammuthus or Mammut sp. (tentative)

Weathered fossil fragment, possibly bone

Indeterminate fossilized bone; likely mineralized vertebrate bone (apatite-rich)

Fossil shell fragment, likely bivalve or gastropod

Indeterminate molluscan fossil; original shell likely aragonite or calcite (CaCO₃)

Fossiliferous limestone with a bivalve fossil

Calcareous sedimentary rock; likely molluscan shell fossil, composed chiefly of calcite (CaCO₃)

Petrified wood

Silicified wood; commonly quartz (SiO₂) replacing original woody tissue

Fossilized mammalian tooth

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

Fossilized dinosaur eggs (probable replicas or heavily prepared specimens)

Fossilized dinosaur eggshell, commonly attributed to sauropod or theropod eggs; exact taxon cannot be determined visually

Fossil brachiopod shell

Likely spiriferid or strophomenid brachiopod; calcium carbonate (primarily calcite)

Fossilized bone fragment

Mineralized vertebrate bone, commonly hydroxyapatite partly replaced by silica or calcite

Petrified wood

Silicified wood, commonly quartz (SiO₂) replacing woody tissue

Fossil Coral (Petoskey Stone or Chain Coral Pebble)

Hexagonaria percarinata / Rugosa coral (CaCO3)

Polished petrified wood

Silicified wood; commonly quartz/chalcedony (SiO₂) replacing cellular tissue

Fossilized bone fragment

Mineralized vertebrate bone, likely mammalian; exact taxon indeterminate

Fossilized rugose coral (horn coral)

Rugosa, class Anthozoa; commonly solitary horn corals

Fossilized shark teeth in sedimentary matrix

Elasmobranchii teeth, chiefly shark; calcium-phosphate apatite (hydroxyapatite)

Crinoid Stem Fossil

Crinoidea (Class) / Calcite (CaCO3)

Fossil shark teeth

Likely fossilized shark teeth; exact species indeterminate from the image, possibly Carcharhiniformes or related taxa

Fossil shark teeth

Probably fossilized shark teeth, possibly *Otodus* or *Carcharhinus* species