Limestone

Crushed Limestone

Calcite-rich Sedimentary Rock (CaCO3)

Oolitic Limestone

Oolite (Sedimentary Calcium Carbonate)

Chert (and Limestone)

Silicon Dioxide (SiO2)

Oolitic Limestone

Oolite (Sedimentary Calcium Carbonate)

Chert

Chert (microcrystalline quartz)

Limestone (specifically Bituminous or Carbonaceous Limestone)

Calcium Carbonate (CaCO3) with Organic Impurities

Chert (with Limestone matrix)

Chert (Silica: SiO2)

Fossiliferous Limestone (Coquina / Shell Limestone)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Chert (Chert Nodule in Limestone)

Microcrystalline Quartz (SiO2)

Chalcedony in Limestone Host Rock

Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Arrowhead Artifact)

Chert (SiO2)

Marble (polished)

Recrystallized Calcite (CaCO3)

Chert (Flint)

Chert (SiO2)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chert (Septarian Nodules / Weathered Silex)

Microcrystalline Quartz (SiO2)

Yellow Calcite

Calcium Carbonate (CaCO3)

Chert (often called Flint)

Chert (Cryptocrystalline Silica, SiO2)

Lapis Lazuli

Lapis Lazuli (a rock composed primarily of Lazurite)

Chert

Microcrystalline Quartz (SiO2)

Chert (Flint)

Chert (Microcrystalline Quartz, SiO2)

Chert (Flint Nodules)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Limestone (Weathered Aggregate)

Sedimentary Carbonate Rock (CaCO3)

Chert (often referred to as Flint or Jasper when pigmented)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Limestone with Calcite Veins

Sedimentary Calcium Carbonate (CaCO3)

Fossilized Fish Skeleton in Matrix

Vertebrata (Class: Actinopterygii), typically found in limestone or shale matrices

Marble

Recrystallized Calcite (CaCO3) Rock

Chert (specifically Yellow/Common Opal or Jasper mixture)

Silicon Dioxide (SiO2)

Marble

Metamorphic rock composed of Recrystallized Carbonate Minerals (chiefly CaCO3)

Banded Chert

Microcrystalline Quartz (SiO2)

Quartz (Chert/Chunky Chalcedony)

Silicon Dioxide (SiO2)

Fluorite

Calcium Fluoride (CaF2)

Lapis Lazuli

Lapis Lazuli (Complex silicate mixture containing Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Lapis Lazuli

Lapis Lazuli (Complex silicate mineral mix including Lazurite, Pyrite, and Calcite)

Sodalite

Sodalite (Sodium Aluminum Silicate Chloride) - Na8(Al6Si6O24)Cl2

Green Chert

Microcrystalline Quartz (SiO2)

Pyrite Geode

Iron Disulfide (FeS2)

Barite

Barium Sulfate (BaSO4)

Lapis Lazuli (polished cabochon/sphere)

Na8[Al6Si6O24]Sn with accessory minerals (Pyrite, Calcite)

Lapis Lazuli

Lapis lazuli (a rock primarily composed of Lazurite, (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Chert (Yellow/Tan)

Microcrystalline Quartz (SiO2)

Orange Calcite

Calcite (Calcium Carbonate, CaCO3)