Sandstone or Limestone
Sedimentary Rock
Category
Browse limestone specimens identified by the Rock Identifier community.
Sandstone or Limestone
Sedimentary Rock
Fossil Shell (Bivalve)
Phylum Mollusca, Class Bivalvia (typically composed of Calcium Carbonate / CaCO3)
Lapis Lazuli
Lapis Lazuli (a rock type, not a single mineral; main component is Lazurite (Na,Ca)8[(S,Cl,SO4,OH)2|(Al6Si6O24)])
Amethyst and Limestone
Amethyst (SiO2 - Silicon Dioxide) and Limestone (CaCO3 - Calcium Carbonate)
Chert (varietal Flint)
Chert (SiO2)
Ooids (Oolites)
Ooids (composed of Calcium Carbonate / CaCO3)
Fossiliferous Limestone Pebble
Calcium Carbonate (CaCO3) with Biogenic Inclusions
Dolomite or Limestone (Carbonate Rock)
CaMg(CO3)2 (Dolomite) or CaCO3 (Limestone / Calcite)
Fossilized Fish (Lepidotes)
Lepidotes sp. (Order: Lepisosteiformes)
Horn Coral Fossil
Order Rugosa
Chert (or Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (and Flint)
Chert (SiO2)
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Belemnite Fossil
Belemnitida (Order within Cephalopoda)
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Chert (Limestone-based)
Silicon Dioxide (SiO2) within Carbonate host
Gray River Pebble (likely Limestone or Siltstone)
Sedimentary Rock (Calcium Carbonate or Siliciclastic)
Zebra Marble
Metamorphosed Limestone (Recrystallized Calcite)
Limestone Cobble
Sedimentary Limestone (Calcium Carbonate, CaCO3)
Chert (v. Flint)
Chert (Microcrystalline Quartz, SiO2)
Septarian Nodule (Dragon Stone)
Septarian Concretion (CaCO3 with Siderite and Calcite)
Chert (Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Fossilized Brachiopod/Bivalve in Limestone
Brachiopoda or Bivalvia fossil in Calcite/Limestone (CaCO3)
Chalk (Limestone)
Calcium Carbonate (CaCO3)
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Biogenic Inclusions
Septarian Nodule
Septarian concretion (Calcite, Aragonite, and Limestone)
Chert / Flint Nodules in Limestone
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)
Chert (often colloquially called Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Limestone Pebble
Limestone (Calcium Carbonate - CaCO3)
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)
Marble
Recrystallized Carbonate Rock (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).
Garden Pebble (Quartzite or Limestone fragment)
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) fragment
Pyrite in Limestone
Iron Sulfide (FeS2) in Calcium Carbonate (CaCO3)
Septarian Nodule (Dragon Stone)
Calcite-Aragonite-Limestone Septarian
Fossiliferous Limestone
Bioclastic Limestone (with Brachiopod and Bivalve molds)
Chert
Microcrystalline Quartz (SiO2)
Lapis Lazuli
Lazurite-rich metamorphic rock (approx. (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)