Mineralized Fossil

River Cobble (likely Metasedimentary or Basalt)

Metamorphosed Siltstone or Altered Fine-grained Igneous Rock

Fossilized Bivalve in Limestone

Class Bivalvia within Sedimentary Matrix (likely CaCO3)

Mammoth Molar Fossil

Mammuthus primigenius (Tooth fragment)

Fossil Coral

Rugose or Tabulate Coral Fossil (CaCO3 replacement)

Fossilized Nut / Coprolite / Concretion

Trace Fossil / Permineralized Plant Material

Fossil ammonite

Ammonite (subclass Ammonoidea; exact species not identifiable from the image)

Fossil Shell

Invertebrate fossil (Mollusca)

Fossil Coral / Crinoid Stem section

Anthozoa / Crinoidea fossil

Fossilized Shark Tooth

Lamniformes (order) fossil

Mixed Mineral and Fossil Collection

Multi-specimen assemblage (SiO2, CaCO3, FeS2, etc.)

Fossiliferous limestone pebble

Bioclastic limestone, chiefly calcite (CaCO₃)

Merlinite (dendritic opal)

Common opal (hydrated amorphous silica, SiO₂·nH₂O) with dark manganese-oxide dendrites; the trade name “merlinite” is also applied to other patterned stones.

Iron-stained quartz rock

Quartz (SiO₂), likely ferruginous quartz or quartz-rich breccia

Iron-stained quartz vein rock

Milky quartz (SiO₂) with limonite/goethite iron oxides, possibly in altered host rock

Ironstone Concretion

Siderite or Hematite Concretion (FeCO3 or Fe2O3)

Weathered sandstone or iron-stained sedimentary rock

Quartz-rich sandstone, possibly ferruginous sandstone

Tumbled fossiliferous limestone

Calcite-rich limestone (CaCO₃), possibly fossiliferous micrite

Turritella Agate (Elimia Agate)

Silicified Elimia tenera (formerly misidentified as Turritella)

Ironstone Nodules / Siderite Concretion

Siderite (FeCO3) / Ferruginous Septarian Concretion

Shark Tooth Fossil

Carcharodon / Otodus fossilized tooth (Calcium Phosphate / Hydroxyapatite)

Quartz-rich breccia or vein quartz specimen

Microcrystalline and crystalline quartz (SiO₂), possibly with iron-oxide staining and minor sulfides

Fossilized cylindrical shell or bone fragment

Indeterminate biogenic carbonate or phosphatic fossil; possible fragment of a tubular shell (e.g., scaphopod) or hollow bone

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Fossilized Bone Fragment

Permineralized Vertebrate Bone (Hydrox yapatite replaced by Silica or Calcite)

Petrified Wood

Silicified Wood (SiO2)

Fossiliferous Limestone containing a Brachiopod or Mollusk Impression

Biogenic Sedimentary Rock / Fossiliferous Limestone

Polished fossilized ammonite or nautiloid shell

Ammonoidea or Nautiloidea; originally aragonitic shell, commonly replaced by calcite or chalcedony

Mosasaur Tooth Fossil

Mosasaurid vertebrate fossil (Hydroxyapatite)

Aragonite cluster (blue aragonite, likely copper-associated)

Aragonite, orthorhombic CaCO₃; blue color may reflect copper minerals or treatment

Weathered limestone fragment

Calcitic limestone (mostly CaCO₃; possibly micritic limestone)

Fossil Shark Tooth

Carcharhinidae or Lamniformes sp. (possibly Carcharodon or Otodus genus)

Black drusy mineral coating, possibly hematite or manganese oxide

Undetermined; likely microcrystalline hematite (Fe₂O₃) or manganese oxides such as pyrolusite (MnO₂)

Brecciated quartzite (likely iron-stained quartz vein material)

Quartzite; predominantly quartz (SiO₂), with dark iron/manganese-oxide or mica-rich seams

Epidosite

Epidosite (Metasomatic calcium-aluminum silicate rock)

Petrified Wood / Fossilized Wood

Silicified Wood (Silicon Dioxide - SiO2)

Petrified Wood

Silicified wood (Quartz, SiO2)

Fossil-bearing limestone, possibly a crinoid or shell fragment

Calcite (CaCO₃) limestone containing an indeterminate marine fossil

Mammoth or Mastodon Tooth Fossil

Mammuthus / Mammut tooth

Fossil-bearing limestone slab

Bioclastic limestone, likely containing brachiopod or bivalve impressions

Fossilized Shark Tooth

Carcharocles sp. (likely Lemon or Sand Tiger)

Shark Tooth Fossil

Carcharocles megalodon or similar fossilized shark tooth

Fossiliferous limestone

Bioclastic limestone, likely containing brachiopod or bivalve impressions