Limestone

Travertine

Terrestrial Sedimentary Limestone (CaCO3)

Fossiliferous Limestone

Sedimentary rock containing Indeterminate Fossil remains (likely Crinoid stem or Bryozoan fragment)

Druzy Quartz on Limestone

Silicon Dioxide (SiO2)

Quartz and Limestone Grouping

Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3)

Fossiliferous limestone pebble

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

Fossilized echinoid (sea urchin), likely a sand dollar fragment or small regular urchin

Echinodermata; commonly Clypeasteroida or Echinoida, preserved mainly as calcite (CaCO₃)

Chert with Limestone matrix

Microcrystalline silica (SiO2) in Calcite (CaCO3) matrix

Veined Limestone

Calcite-veined Limestone (CaCO3)

Fossiliferous Limestone

Calcium Carbonate (CaCO3) - Limestone

Fossiliferous Limestone

Limestone (Calcium Carbonate - CaCO3)

Weathered limestone

Limestone, predominantly calcite (CaCO₃)

Fossiliferous Limestone

Fossiliferous Limestone (Sedimentary Rock)

Fossiliferous Limestone

Limestone (CaCO3 - Calcium Carbonate)

Fossiliferous Limestone

Bioclastic Limestone (composition: CaCO3)

Limestone Pebble

Limestone (Calcium Carbonate, CaCO3)

Slickenside in Limestone

Tectonized Limestone / Calcite (CaCO3)

Fossiliferous Limestone

Fossiliferous Limestone (containing bioclasts)

Fossiliferous limestone

Calcite-rich limestone (CaCO₃), possibly coral or shell-bearing bioclastic limestone

Geode (Unopened)

Quartz Geode (SiO2-rich chalcedony/quartz nodule)

Fossiliferous Limestone

Biogenic Sedimentary Rock (primarily CaCO3 with fossil fragments)

Fossil coral fragment

Fossilized colonial coral, commonly Favositidae or related tabulate coral

Travertine

Travertine (CaCO3)

Fossilized Gastropod in Limestone

Gastropoda (Class) in Calcium Carbonate (CaCO3)

Fossiliferous Limestone (Chert/Clay mixed)

Calcium Carbonate (CaCO3) / Silicon Dioxide (SiO2)

Weathered limestone or calcitic fossil-bearing rock

Calcite-rich limestone, primarily CaCO₃

Fossiliferous limestone pebble

Calcite-rich limestone containing possible brachiopod or coral fossil impressions

Fossilized Gastropod in Limestone

Gastropoda (Class) in Fossiliferous Limestone

Small pale stone fragment (undetermined)

Unidentified; the image lacks diagnostic detail for a reliable identification

Limestone bedrock

Limestone, chiefly calcite (CaCO₃)

Fossiliferous limestone

Calcite-rich limestone (primarily CaCO₃), possibly containing fossil shell or coral fragments

Vuggy Limestone

Carbonate Sedimentary Rock with Vuggy Porosity (CaCO3)

Limestone Pebble

Limestone (Calcium Carbonate - CaCO3)

Weathered light-colored rock pebble, possibly limestone

Likely micritic limestone (calcium carbonate, CaCO₃); exact identification is uncertain from the photograph

Chert Nodules in Limestone

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Mosasaur Tooth Fossil

Mosasaurus sp.

Likely limestone

Calcite-rich limestone (primarily CaCO₃); identification from the photo is tentative

Small pale mineral fragment, likely quartz or calcite

Tentatively quartz (SiO₂) or calcite (CaCO₃); image resolution prevents confident identification

Lapis Lazuli

Lapis Lazuli (Rock composed mainly of lazurite, calcite, and pyrite)

Orange Calcite

Calcium Carbonate (CaCO3)

Lapis Lazuli (or Sodalite)

Lapis Lazuli (principally Lazurite: Na6Ca2(Al6Si6O24)S2)

Chert

Microcrystalline Quartz (SiO2)

Flint

Sedimentary cryptocrystalline quartz (SiO2)