Sedimentary (Chemically Precipitated)

Jasper

Microcrystalline Quartz (SiO2)

Oolitic Limestone (Egg Stone)

Oolite (Chemical sedimentary rock, primarily CaCO3)

Sandstone with Liesegang Rings

Clastic Sedimentary Rock with Iron Oxide Precipitates (SiO2 + Fe2O3)

Green Calcite

Calcium Carbonate (CaCO3)

Chert pebble

Microcrystalline silica (SiO2)

Chert (Flint)

Chert (Cryptocrystalline Quartz, SiO2)

Green Calcite

Calcium Carbonate (CaCO3)

Chert (Iron-stained)

Silicon Dioxide (SiO2)

Banded Chert

Microcrystalline Quartz (SiO2)

Chert Pebble with Quartz Veins

Microcrystalline Quartz (SiO2)

Chert (Black Chert)

Microcrystalline Silica (SiO2)

Banded Onyx (Cave Calcite)

Calcite (CaCO3), often called Mexican Onyx or Travertine

Banded Chert

Microcrystalline Quartz (SiO2)

Marcasite on Agate / Sphalerite-Pyrite Agate Geode Slice

Marcasite (FeS2) / Pyrite on Quartz (SiO2)

Blue Calcite

Calcium Carbonate (CaCO3)

Clear Quartz

Silicon Dioxide (SiO2)

Honey Calcite

Calcium Carbonate (CaCO3)

Jasper with Quartz Vein

Microcrystalline Quartz (SiO2)

Chert (Flint)

SiO2 (Microcrystalline Quartz)

Red Jasper

SiO2 (Microcrystalline Quartz)

Quartz

Silicon Dioxide (SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Quartz-encrusted Matrix

Silicon Dioxide (SiO2) with Ferruginous Sandstone

Sandstone (Ferruginous Concretion)

Arenite (with iron oxide cement)

Weathered limestone

Calcite-rich limestone (primarily CaCO₃)

Chert (with Manganese Dendrites)

Chert (Cryptocrystalline Quartz, SiO2)

Chert Nodule / Flint

Microcrystalline Quartz (SiO2)

Chert (and Flint)

Silicon Dioxide (SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Limonite (Iron Ore)

Limonite (Iron oxide-hydroxide mixture, FeO(OH)·nH2O)

Orange Calcite

Calcium Carbonate (CaCO3)

Banded Iron Formation (BIF) with Quartz

Banded Iron Formation, often composed of alternating layers of hematite (Fe2O3) or magnetite (Fe3O4) and chert (microcrystalline quartz, SiO2)

Chert (River Pebble)

Chert (Cryptocrystalline Quartz, SiO2)

Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')

Calcite (Calcium Carbonate, CaCO3)

Yellow Jasper / Chert

Silicon Dioxide (SiO2) with Goethite or Limonite inclusions

Aragonite Star Cluster

Aragonite (Calcium Carbonate, CaCO3)

Chert (Nodular)

Microcrystalline Quartz (SiO2)

Quartz Geode (Cracked Open Fragment)

Silicon Dioxide (SiO2)

Calcite

Calcium Carbonate (CaCO3)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Banded Chert (Jasper) River Pebble

Microcrystalline Quartz (SiO2)

Jasper

Microcrystalline Quartz (SiO2)