Sedimentary (Matrix)

Brachiopod Fossil in Sedimentary Matrix

Phylum Brachiopoda in Siltstone/Mudstone matrix

Bivalve Fossil in Sedimentary Matrix

Fossiliferous Mudstone (Class: Bivalvia)

Fossil Shell in Sedimentary Matrix

Bivalvia (fossil) in Calcium Carbonate Matrix

Quartz Geode in Sedimentary Matrix

Silicon Dioxide (SiO2) within a limestone/dolostone host

Quartz Vein in Sedimentary Matrix

Silicon Dioxide (SiO2) with host rock

Botryoidal Hematite (Iron Stone Conglomerate)

Hematite (Fe2O3) in sedimentary matrix

Quartz, Sandstone, and Siltstone specimens

Silicon Dioxide (SiO2) and Clastic Sedimentary Rocks

Chert with Limestone

Microcrystalline Quartz (SiO2) in Calcium Carbonate (CaCO3) matrix

Dendritic sandstone

Sandstone with Manganese Oxide dendrites

Hag Stone

Siltstone or Fine-grained Sandstone with boring (e.g., Lithophaga impact)

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Fossiliferous Limestone with Brachiopod

Phylum Brachiopoda in Sedimentary Matrix (CaCO3)

Pyrite Concretion

Iron Sulfide (FeS2) in Sedimentary Matrix

Turritella Gastropod Fossil

Turritella (mollusk fossil in sedimentary matrix)

Sandstone (with Iron Oxide)

Quartz Arenite / Ferruginous Sandstone (SiO2 with Fe2O3)

Fern fossil in shale

Plant fossil, likely a fern frond impression preserved in fine-grained shale; exact species indeterminable from the image

Fossiliferous Limestone with Brachiopod

Phylum Brachiopoda in Sedimentary Matrix (CaCO3)

Fossilized Limestone with Crinoid Stem

Carboniferous Limestone (containing Crinoidea ossicles)

Gastropod Fossil (Internal Mold)

Phylum Mollusca, Class Gastropoda (Steinkern)

Fossilized Rugose Coral in Limestone

Order Rugosa in Sedimentary Matrix (CaCO3)

Quartz Vein in Host Rock

Quartz (SiO2) in Mafic or Sedimentary Matrix

Quartz Vein in Siltstone

SiO2 (Quartz) on clastic sedimentary matrix

Megalodon Shark Tooth Fossil

Otodus megalodon (fossilized in sedimentary matrix)

Limestone with Calcite Vug

Calcium Carbonate (CaCO3) in Sedimentary Matrix

Geode

Crystalline Quartz in Sedimentary Matrix (SiO2)

Pyrite in Shale

Iron Sulfide (FeS2) in Sedimentary Matrix

Fossil ammonite or gastropod cast

Ammonoidea or fossil gastropod; exact identification requires clearer details

Fossilized turtle shell or carapace

Testudines indeterminate; shell mainly fossilized calcium-carbonate bone (apatite)

Limestone (or Sandstone)

Calcium Carbonate (CaCO3) / Silica (SiO2)

Fossiliferous Sandstone / Fossil Fragment

Fossiliferous Sedimentary Matrix with Indeterminate Fossil Material

Fossilized shark teeth in sedimentary matrix

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

Quartz Vein in Host Rock (likely Sandstone or Mudstone)

Silicon Dioxide (SiO2) within Sedimentary Matrix

Fossilized Shark Teeth in Matrix

Cretaceous Chondrichthyes (Shark) remains in Sedimentary Matrix

Iron-rich concretion or weathered ironstone

Limonite/goethite-rich ironstone; commonly hydrated iron oxides such as FeO(OH)·nH₂O

Fossil bivalve shell in matrix

Likely fossilized oyster or mussel (Bivalvia), with a nacreous aragonite shell; exact genus and age require locality and preparation details

Dinosaur Skull Fossil (Velociraptor Replica)

Velociraptor mongoliensis fossil specimen in sedimentary matrix

Fossiliferous Concretion

Septarian Concretion containing Brachiopods/Crinoids

Fossiliferous shale or mudstone with plant fossils

Carbonaceous mudstone/shale containing fossilized foliage, likely fern or seed-fern impressions

Fossilized Trilobite or Mollusk Fragment

Phylum Arthropoda / Mollusca fossil in sedimentary matrix

Quartz Geode

Crystalline Silicon Dioxide (SiO2) in sedimentary matrix

Dinosaur Fossil (Tyrannosaurus rex skull replica/specimen)

Tyrannosaurus rex (fossilized in permineralized sedimentary matrix)

Brachiopod Fossil in Sedimentary Rock

Phylum Brachiopoda fossil imprint in sedimentary matrix