Sedimentary (Fossiliferous)

Limestone

Calcium Carbonate (CaCO3)

Coquina

Bioclastic Limestone (composed primarily of Calcium Carbonate / CaCO3)

Iron-stained fossiliferous rock, possibly fossil wood

Likely silicified/petrified wood in iron-rich silica matrix; exact identification requires microscopy

Fossiliferous limestone, likely coral or shell-rich fragment

Calcite (CaCO₃), commonly bioclastic limestone containing fossilized marine organisms

Limestone with possible fossil inclusions

Sedimentary Calcium Carbonate (CaCO3)

Likely tumbled sandstone or limestone

Quartz-rich sandstone (possibly calcarenite/limestone)

Limestone

Calcite-dominated limestone (CaCO₃), possibly impure or fossiliferous limestone

Fossiliferous limestone, likely coral limestone

Bioclastic calcite (CaCO₃), commonly derived from fossil coral or shell material

Trilobite Fossil in Limestone

Trilobita (Class), likely embedded in fossiliferous limestone (CaCO3)

Weathered coal-bearing sedimentary rock (likely shale or mudstone with coal fragments)

Carbonaceous shale/mudstone; predominantly clay minerals, quartz, and organic carbon

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with marine fossils

Weathered sandstone or iron-rich sedimentary rock

Clastic sandstone, likely ferruginous sandstone; primarily quartz (SiO₂) with iron-oxide cement

Fossiliferous Limestone (Coral Rag)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone (Gritstone/Marl)

CaCO3 (Calcium Carbonate) with Fossil Inclusions

Fossiliferous Limestone (Coquina-like)

Biogenic Limestone

Fossiliferous Limestone (Coral Fossil)

Scleractinian Coral in Calcium Carbonate (CaCO3)

Fossiliferous Limestone (Red Marble)

Bioclastic Limestone (CaCO3)

Fossiliferous Limestone (Shell Fragment)

Biogenic Limestone (Calcium Carbonate / CaCO3)

Fossiliferous Chert (Gryphaea Fossil)

Silicon Dioxide (SiO2) with Calcitic Mollusk Remnants

Weathered sandstone or fine-grained graywacke

Clastic sedimentary rock; chiefly quartz (SiO₂), feldspar, and lithic fragments bound by silica, calcite, or iron-oxide cement

Weathered limestone fragment

Calcitic limestone, primarily calcium carbonate (CaCO₃; mineral calcite)

Weathered limestone

Calcite-rich carbonate rock; primarily CaCO₃

Likely limestone or chalky carbonate rock

Calcite-rich carbonate rock; chiefly calcium carbonate (CaCO₃)

Weathered limestone or calcareous rock

Calcite-rich carbonate rock; primarily calcium carbonate (CaCO₃)

Light-colored weathered stone, likely limestone

Limestone, predominantly calcite (CaCO₃)

Mixed limestone and sandstone specimens

Mostly calcitic limestone (CaCO₃), with possible quartz-rich sandstone and iron-oxide staining

Weathered porous sandstone or tuff

Indeterminate siliciclastic rock, likely quartz-rich sandstone; possibly volcanic tuff

Weathered sandstone or iron-rich sedimentary rock fragments

Quartz-rich sandstone, locally ferruginous; exact identification requires testing

Weathered sandstone cobble

Clastic sandstone, likely quartz-rich arenite or arkose

Red sandstone fragment

Ferruginous sandstone, chiefly quartz (SiO₂) with iron-oxide cement

Weathered sandstone

Quartz-rich sandstone, likely arkose or lithic sandstone

Chert (likely flint-bearing chert)

Microcrystalline quartz, SiO₂ (chalcedony/quartz aggregate)

Weathered sandstone pebble

Quartz-rich sandstone, likely ferruginous litharenite

Limestone

Calcium Carbonate (CaCO3)

Sandstone (lithic wacke/arenite)

Clastic sedimentary rock (SiO2 + varied clasts)

Weathered sandstone or iron-rich sedimentary rock

Quartz-rich sandstone, likely ferruginous sandstone; composition mainly SiO₂ with iron oxides

Reddish sandstone

Quartz-rich sandstone (arenite), commonly iron-oxide stained

Limestone

Calcium Carbonate (CaCO3)

Likely limestone or marble

Calcite-rich carbonate rock; chiefly calcium carbonate, CaCO₃

Banded chert or siliceous shale

Microcrystalline quartz (SiO₂), possibly interbedded with carbonaceous or clay-rich shale

Weathered limestone

Calcite-rich carbonate rock (primarily CaCO₃)

Conglomeratic sandstone or breccia specimen

Quartz-rich clastic sedimentary rock; likely sandstone with pebble-sized quartz, feldspar, and lithic clasts