Mineral (Biogenic Replacement)

Polished black stone, possibly black jasper or obsidian

Uncertain; candidates include microcrystalline quartz (SiO₂; black jasper) or volcanic glass (obsidian, SiO₂)

Weathered iron-rich rock fragment

Indeterminate; likely limonite/goethite-bearing rock, possibly altered basalt or ironstone

Galena

Lead sulfide (PbS)

Jasper

Silicon dioxide (SiO2) with impurities

Galena

Lead(II) sulfide (PbS)

Tumbled metallic sulfide specimen, likely galena

Galena (lead sulfide, PbS), possibly mixed with pyrite or other sulfides

Metallic sulfide mineral specimen, possibly pyrite

Likely pyrite (FeS₂), though the photograph is insufficient for certainty

Uncertain dark metallic mineral specimen

Possibly galena (lead sulfide, PbS), though the image is too blurred for reliable identification

Possible flint or slag fragment

Microcrystalline quartz (chalcedony), or iron-rich industrial slag

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Pyrite (on Quartz/Host Rock)

Iron Sulfide (FeS₂)

Tooth fossil, likely mammalian or reptilian fragment

Indeterminate fossilized tooth; enamel and dentine, taxon unresolved

Bivalve Fossil (Clam)

Class Bivalvia (Mollusca)

Fossilized gastropod (snail)

Gastropoda indet.; likely a mineral-replaced or steinkern fossil

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood / Chalcedony (SiO2)

Chert (varietal Jasper or Mudstone Flint)

Silicon dioxide (SiO2) with impurities

Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Chert Geode or Nodule

Microcrystalline Quartz (SiO2)

Flint

Silicon Dioxide (SiO2) - variety of Chert

Fossil Shell (Bivalve)

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

Fossilized Coral (Favosites)

Favosites (extinct genus of tabulate coral)

Fossilized bone

Petrified bone; commonly fossil vertebrate bone composed largely of hydroxyapatite and silica/calcite replacement minerals

Likely fossilized bone or tooth fragment

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

Goethite–limonite ironstone

Goethite (α-FeO(OH)) with limonite, hydrated iron oxides, and possible quartz

Hematite (Botryoidal/Kidney Ore)

Iron(III) oxide (Fe2O3)

Chalcedony Nodule (Commonly known as Agate or Chert)

Microcrystalline Quartz (SiO2)

Fossil coral or stromatoporoid fragment

Likely fossilized colonial coral; exact taxon indeterminate from image

Fossil bivalve shell

Fossilized or calcitic bivalve, likely a scallop-type pectinid (Bivalvia: Pectinidae)

Fossil bivalve or brachiopod in sedimentary rock

Unidentified fossil shell impression; likely a ribbed bivalve or brachiopod preserved in shale/siltstone

Petoskey Stone

Hexagonaria percarinata

Chert (or Jasper)

Microcrystalline Quartz (SiO2)

Galena

Lead(II) sulfide (PbS)

Weathered fossil shell fragment

Likely a bivalve or gastropod shell, composed mainly of biogenic calcite/aragonite (CaCO₃)

Chert

Microcrystalline Quartz (SiO2)

Chert

Chert (Microcrystalline Quartz, SiO2)

Fossilized shell, likely brachiopod or bivalve

Indeterminate fossil shell; possible Spiriferida brachiopod or thick-shelled bivalve

Chert (Flint)

Microcrystalline Quartz (SiO2)

Green Jasper

Silicon Dioxide (SiO2) with iron silicate inclusions

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Tiger's Eye

Pseudomorph of quartz after crocidolite (SiO2 with iron inclusions)

Chert Pebble with Quartz Veins

Microcrystalline Quartz (SiO2)

Fossil oyster shell

Bivalvia; likely an oyster (Ostreidae), preserved mainly as calcite/aragonite shell