Mineral (Biogenic Replacement)

Flint

Microcrystalline Quartz (SiO2)

Metallic sulfide-bearing rock, possibly galena-bearing ore

Probable galena (PbS) with pyrite and quartz/matrix; exact identification requires testing

Iron-rich breccia or weathered ironstone

Goethite–hematite-bearing limonite, possibly brecciated host rock

Pyrite

Iron Disulfide (FeS2)

Fossil bone fragment (likely vertebrate bone)

Fossilized vertebrate bone; exact taxon indeterminate from the photograph

Tooth or bone fragment (likely animal tooth)

Indeterminate vertebrate tooth; possibly a small mammal or fish tooth

Banded Chert

Silicon Dioxide (SiO2) with impurities

Fossil scallop shell

Pectinid bivalve fossil; likely a scallop (family Pectinidae), exact genus/species uncertain

Petrified Wood

Silicified Wood (SiO2)

Fossilized Shark Tooth

Chondrichthyes (class) fossilized tooth

Fossilized Bark

Lepidodendron / Sigillaria fossil impression

Polished leopard-skin jasper

Leopard-skin jasper; an opaque, microcrystalline quartz-rich rock, commonly with iron-oxide and volcanic/mineral inclusions

Fossil bivalve shell, likely oyster or related mollusk

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

Pyrite with Galena and Sphalerite on Matrix

Iron Sulfide (FeS2), Lead Sulfide (PbS), Zinc Sulfide (ZnS)

Petrified Wood

Silicified Wood (SiO2)

Fluorite

Calcium Fluoride (CaF2)

Polished fossil shell fragment (likely ammonite or bivalve)

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

Fossilized Bone

Permineralized Bone (Vertebrate Fossil)

Tumbled brown stone, likely brown jasper or iron-rich chert

Microcrystalline quartz (SiO₂), possibly hematite/goethite-bearing

Galena

Galena (lead sulfide, PbS)

Galena

Galena (lead sulfide, PbS)

Galena-bearing sulfide ore

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

Likely galena-bearing ore

Galena (lead sulfide, PbS), possibly with quartz or calcite gangue

Rhodonite

Rhodonite (Mn,Fe,Mg,Ca)SiO3

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

Rhodonite

Manganese silicate (Mn,Fe,Mg,Ca)SiO3

Tiger's Eye

SiO2 (Silicon Dioxide) with fibrous crocidolite inclusions

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Fossilized shell or coral fragment

Indeterminate marine mollusk or colonial coral fossil; likely calcite/aragonite replaced by calcite (CaCO₃)

Fossilized Shark Tooth (Megalodon or Carcharocles fragment)

Elasmobranchii (Fossilized tooth root / crown section)

Fuchsite

Cr-bearing Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Gastropod Fossil (Snail Stone or Steinkern)

Class Gastropoda (Calcium Carbonate - CaCO3 / Silica - SiO2 replacing original shell)

Fossilized tooth or tooth fragment

Indeterminate vertebrate tooth; possibly a fossil shark tooth (Carcharodon/Carcharocles)

Fossil bivalve shell

Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features

Banded Chert

Microcrystalline Quartz (SiO2)

Polished orbicular jasper (likely ocean jasper)

Jasper, microcrystalline quartz (SiO₂), with iron-oxide and other silicate inclusions

Chert (Flint) with Limonite Staining

Microcrystalline Quartz (SiO2)

Chert / Jasper

Silicon Dioxide (SiO2)

Weathered quartz-rich rock, likely silicified limestone or quartzite

Microcrystalline quartz (SiO₂), possibly with calcite (CaCO₃) and iron-oxide staining

Fossilized shell fragment

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

Fossilized tooth, likely shark tooth

Fossil selachian tooth; possibly Otodus/Carcharocles or related shark, identification uncertain from image

Galena-bearing ore

Galena (lead sulfide, PbS), likely with quartz/carbonate gangue and weathered sulfides