Limestone

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

Nephrite Jade

Tremolite-actinolite series (Ca2(Mg,Fe)5Si8O22(OH)2)

Painted River Rock

Anthropogenic-modified Siliciclastic Sedimentary Rock

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Yellow Calcite

Calcium Carbonate (CaCO3)

Chert (Yellow or Tan variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (and Flint)

Silicon Dioxide (SiO2)

Chert (Jasper/Flint variant)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Orthoceratid Fossil in Limestone

Orthoceras (extinct genus of Nautiloid Cephalopod)

Coquina or Fossiliferous Limestone

Biogenic Limestone (Calcite/Aragonite CaCO3)

Coquina

Biogenic Limestone (Calcium Carbonate - CaCO3)

Coquina

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone (Coquina)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Coquina / Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate - CaCO3)

Coquina

Biogenic Limestone (Calcium Carbonate, CaCO3)

Coquina with Shell Fragment

Bioclastic Limestone (composed primarily of CaCO3)

Coquina

Biogenic Limestone (Calcium Carbonate, CaCO3)

Coquina

Bioclastic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone (Coquina)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossiliferous Limestone (containing Brachiopods)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Fossilized Shell in Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Chalk (Sedimentary Pebble)

Calcium Carbonate (CaCO3) - Biogenic Limestone

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Fossiliferous Limestone (Coquina / Shell Bed)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Chert (specifically Flint)

Silicon Dioxide (SiO2)

Chert (Yellow Jasper variant)

Microcrystalline quartz (SiO2)

Chert (Nodular)

Cryptocrystalline Quartz (SiO2)

Chert (containing Flint and Calcareous inclusions)

Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) impurities

Chert / Flint Nodules

Chert (Cryptocrystalline variety of Quartz, SiO2)

Chert (Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Chert (White Chert / Flint)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

Chert (often called Flint)

Microcrystalline to cryptocrystalline quartz (SiO2)

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Fossilized Gastropod in Chert/Limestone

Internal mold of Gastropoda (Class) with CaCO3 or SiO2 mineral formula

Chert (variations include Flint/Chalcedony)

Chert (SiO2 - Silicon Dioxide)

Chert (often referred to as Flint)

Chert (Microcrystalline or cryptocrystalline Quartz, SiO2)

Chert (specifically Flint or Chalcedony nodule)

Microcrystalline Quartz (SiO2)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Hag Stone

Calcareous sedimentary rock (often Chert, Flint, or Limestone)

Calcite

Calcite (CaCO₃)