Limestone
Sedimentary Calcium Carbonate (CaCO3)
Category
Browse sedimentary (fossiliferous) specimens identified by the Rock Identifier community.
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Fossiliferous Limestone with Brachiopod Mold
Calcium Carbonate (CaCO3) matrix containing Brachiopoda fossil impressions
Fossiliferous Limestone with Rugose Coral
Calcite (CaCO3) containing a Rugosa (Horn Coral) fossil
Fossiliferous Sandstone (with Brachiopod or Bivalve mold)
Clastic Sedimentary Rock with Macrofossil Mold
Fossiliferous Limestone with Rugose Coral
Lithostrotionella (Limestone Matrix - CaCO3)
Fossiliferous Limestone with Rugose Coral
Rugosa (order), typically preserved in CaCO3 (Calcite)
Fossiliferous Limestone with Crinoid Stem
Bioclastic Limestone (CaCO3)
Fossiliferous Limestone (Crinoidal Limestone)
Bioclastic grainstone (CaCO3)
Fossiliferous Limestone (containing Brachiopods)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Fossiliferous Limestone with Brachiopod shell
Calcium carbonate (CaCO3)
Crushed Limestone
Calcite-rich Sedimentary Rock (CaCO3)
Weathered fossiliferous limestone pebble
Calcitic limestone, predominantly CaCO₃ (likely containing fossil or bioclast fragments)
Fossiliferous Mudstone / River Pebble
Sedimentary rock with trace fossil or inclusion
Chert (Fossiliferous Chert/Flint)
Silicon Dioxide (SiO2)
Chert or flint fragment
Microcrystalline quartz (SiO₂), likely silicified rock
Limestone
Calcium Carbonate (CaCO3)
Banded limestone or marble
Calcite-dominated carbonate rock; likely banded marble (CaCO₃)
Fossiliferous Chert (Brachiopod/Bryozoan Fossil)
Microcrystalline quartz (SiO2) with fossil inclusions
Flint / Chert (or fossiliferous nodule)
Microcrystalline quartz (SiO2)
Fossiliferous Limestone (Coral Fossil)
Calcium Carbonate (CaCO3) with Colonial Coral inclusions
Weathered limestone fragment
Calcite-rich limestone, primarily calcium carbonate (CaCO₃)
Weathered limestone or calcitic cave deposit
Calcite (CaCO₃), likely porous limestone/travertine
Limestone
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Coquina
Bioclastic Limestone (composed primarily of Calcium Carbonate / CaCO3)
Sandstone
Arenite
Weathered sandstone or quartz-rich sedimentary pebble
Indeterminate lithic fragment; likely quartz arenite (sandstone)
Weathered limestone
Limestone, predominantly calcite (CaCO₃)
Likely weathered sandstone or iron-stained sedimentary fragment
Quartz-rich sandstone; exact identification requires testing
Tumbled, weathered limestone or calcareous concretion
Calcite-rich limestone; predominantly calcium carbonate (CaCO₃)
Limestone
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Glauconitic Sandstone (Greensand pebble)
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
Brachiopod Fossil in Limestone
Phylum Brachiopoda (likely Order Spiriferida), CaCO3 (Calcite)
Weathered sandstone or iron-stained sedimentary rock
Likely quartz-rich sandstone; exact identification is uncertain from the photograph
Fossil-bearing Sedimentary Rock
Sedimentum cum fossili
Limestone with possible fossil inclusions
Sedimentary Calcium Carbonate (CaCO3)
Likely tumbled sandstone or limestone
Quartz-rich sandstone (possibly calcarenite/limestone)
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with marine fossils
Tumbled limestone pebble
Limestone, primarily calcite (CaCO₃)