Limestone

Lapis Lazuli

Lazurite-rich metamorphic rock; (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2

Lapis Lazuli

Na8[Al6Si6O24]n(S,Cl,SO4,OH)2

Marble

Recrystallized Calcite (CaCO3)

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Limestone-based)

Silicon Dioxide (SiO2) within Carbonate host

Weathered sandstone or limestone fragment

Indeterminate clastic carbonate/siliciclastic rock; likely quartz-rich sandstone or porous limestone

Orange Calcite

Calcium Carbonate (CaCO3)

Limestone Concretion (Botryoidal/Calcareous Nodules)

Calcium Carbonate Concretion (CaCO3)

Crinoid Fossil in Limestone

Crinoidea (Phylum Echinodermata) in Calcite Matrix (CaCO3)

Chert (and Fossiliferous Limestone)

Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)

Septarian Nodule (Dragon Stone)

Carbonate concretion (Calcite and Aragonite in Limestone/Clay)

Chert or flint fragment

Microcrystalline quartz (SiO₂), likely silicified rock

Bivalve Internal Mold Fossil

Steinkern (Bivalvia mold)

Crinoid Fossil

Crinoidea (Echinodermata)

Flint (or Chert with Chalk/Limestone)

Microcrystalline quartz (SiO2) nodule

Fossiliferous Limestone

Bioclastic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone

Bioclastic Limestone (Calcium Carbonate, CaCO3)

Lapis Lazuli

Lapis Lazuli (a rock composed primarily of Lazurite (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2, with varying amounts of Calcite, Pyrite, and Sodalite).

Calcite

Calcium Carbonate (CaCO3)

Porous limestone

Calcareous limestone, primarily calcite (CaCO₃)

Chalky limestone

Micritic limestone, predominantly calcite (CaCO₃)

Chalky limestone

Micritic calcite limestone; predominantly CaCO₃

Fossiliferous limestone

Bioclastic limestone, primarily calcite (CaCO₃)

Fossiliferous Limestone

Fossiliferous Limestone (CaCO3 with organic inclusions)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone

Bioclastic Limestone (with Brachiopod and Bivalve molds)

Fossiliferous Limestone

Biogenic Limestone with Brachiopod/Crinoid fragments

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Coquina Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Carved Stone

Orthoceras Fossil

Orthoceras sp. (Extinct genus of nautiloid cephalopod)

Limestone (River Stone)

Calcium Carbonate (CaCO3)

Limestone (with possible Manganese oxide inclusions)

Sedimentary Calcium Carbonate (CaCO3)

Limestone (specifically a Crushed Aggregate fragment)

Calcium Carbonate (CaCO3)