Mineral Like Biological Tissue

Chert (Greenish-Grey variety)

Microcrystalline quartz (SiO2)

Flint in Limestone (Chert Nodule)

Sedimentary rock containing microcrystalline quartz (SiO2) within a carbonate matrix

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Petrified Wood

Silicified Wood / Xylopal

Seashell fragment

Calcium carbonate (CaCO3)

Fossiliferous Limestone

CaCO3 (with biological inclusions)

Amber

Succinite (with approximate formula C10H16O)

Banded agate (likely petrified wood)

Silicified wood, chiefly microcrystalline quartz (SiO₂), with iron-oxide inclusions

Fossil tooth, likely mammalian molar or premolar

Mineralized fossilized tooth; exact taxon cannot be determined from the image

Fossiliferous Limestone with Rugose Coral

Calcite (CaCO3) matrix containing Rugosa (order of extinct solitary and colonial corals)

Limestone

CaCO3 (Mainly Calcite or Aragonite)

Petrified wood

Silicified wood, commonly quartz/chalcedony (SiO₂) replacing woody tissue

Banded chert (likely jasper/chalcedony-rich stone)

Microcrystalline quartz, SiO₂, with iron-oxide impurities

Fossilized bone, likely a large mammal limb bone

Mineralized cortical bone; exact taxon indeterminate from the image

Fossiliferous limestone pebble

Calcite-rich limestone (primarily CaCO₃), with possible fossil or fossil-fragment patterns

Fossiliferous Limestone

Fossiliferous Calclutite / Bio-calcarenite (CaCO3)

Weathered fossiliferous limestone, likely coral or shell fragment

Calcite (CaCO₃), biogenic limestone; exact fossil taxon indeterminate from the image

Amber

Succinite (Fossilized Tree Resin)

Fossilized Horse Tooth

Equus sp. (Tooth)

Weathered iron-rich sandstone or ferruginous pebble

Quartz-rich sandstone with iron-oxide cement; exact identification requires testing

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Fossiliferous Sandstone

Sedimentary rock containing invertebrate fossils

Orange Calcite

Calcium Carbonate (CaCO3)

Fossil Shark Tooth

Chondrichthyes (Class)

Pyrite (on host rock/ore)

Iron Sulfide (FeS2)

Polished petrified wood

Silicified wood; primarily microcrystalline quartz (SiO₂) replacing woody tissue

Fossiliferous Brachiopod in Shale

Brachiopoda (Phylum) preserved in Carbonaceous Shale

Chert (containing fossil leaf impression)

Microcrystalline silicon dioxide (SiO2)

Vesicular volcanic rock, likely pumice or scoriaceous rhyolite

Silica-rich vesicular volcanic rock; commonly rhyolitic pumice (SiO₂-rich glass)

Fossilized Rugose Coral (Petoskey Stone type)

Hexagonaria percarinata (Order: Rugosa)

Fossiliferous Concretion

Septarian Concretion containing Brachiopods/Crinoids

Amber

Succiniferous fossil resin (C10H16O)

Petrified wood

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

Chert (Yellow Jasper variant)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Fossil coral or shell fragment

Indeterminate calcareous fossil; likely aragonite or calcite (CaCO₃)

Fossiliferous Limestone with Brachiopod

Limestone (Calcium Carbonate, CaCO3) with Phylum Brachiopoda fossil

Fossilized Coral (Petoskey Stone / Favosites)

Hexagonaria percarinata / Favosites sp. (Calcite, CaCO3)

Turquoise and Red Coral

Turquoise: CuAl6(PO4)4(OH)8·4H2O; Red Coral: Corallium rubrum (organic gemstone)

Natural Freshwater Pearl

Calcium Carbonate (Aragonite and Calcite), CaCO3

Pyrite

Iron Disulfide (FeS2)

Pumice

Pumicite (Amorphous glass with varying chemical composition, often rhyolitic)

Petrified wood (polished/cut slab)

Silicified fossil wood, commonly quartz/chalcedony (SiO₂) replacing wood tissue