Sedimentary (Synthetic)

Coal (Bituminous or Anthracite)

Carbonaceous sedimentary rock (primarily Carbon, C)

Sandstone (Ferruginous)

Arenite (Fe-bearing Clastic Sedimentary Rock)

Sandstone (with potential fossil inclusions)

Clastic sedimentary rock (primarily SiO2)

Banded Chert

Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)

Chalk

CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock

Sandstone

Arenite

Sandstone (Weathered Pebble)

Arenite (composed primarily of SiO2)

Quartz Vein in Sedimentary Matrix

Silicon Dioxide (SiO2) with host rock

Sandstone

Sandstone (Sedimentary rock composed of silicate grains)

Conglomerate

Clastic sedimentary rock (Polymictic Conglomerate)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Bituminous Coal

Organic Sedimentary Rock (Carbon-based)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2)

Chert (within Limestone)

Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)

Sandstone (River Rock)

Arenite (SiO2 principal component)

Limestone Fragment

Sedimentary rock (primarily Calcium Carbonate, CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Quartzite

Quartzite (SiO2)

Sandstone

Arenite (SiO2 based)

Shale

Shale (composition varies: primarily clay minerals and quartz)

Chert (Jasper variation)

Chert (Microcrystalline Silicon Dioxide, SiO2)

Fossiliferous Limestone

Biogenic Calcium Carbonate (CaCO3)

Sandstone with Iron Oxide

Arenite (SiO2 with Fe2O3 staining)

Banded Iron Formation (BIF) / Iron Ore

Banded Iron Formation (composed primarily of Hematite (Fe2O3) and Magnetite (Fe3O4) with Quartz/Chert)

Sandstone (Greywacke)

Sandstone (SiO2 enriched with lithic fragments)

Celadonite in Basalt (Green Earth)

Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)

Hematite

Hematite, Iron(III) oxide (Fe2O3)

Sandstone (Ferruginous)

Arenite (Fe2O3 rich)

Coarse Sandstone

Arenite (SiO2 based)

Sandstone (likely Quartz Sandstone)

Arenite (SiO2 based)

Sandstone

Arenite (Sedimentary rock composed of sand-sized minerals or rock grains)

Chert (often called Flint when dark)

Sedimentary cryptocrystalline quartz (SiO2)

Limonite / Ironstone Nodule

Limonite (Hydrated iron(III) oxide-hydroxide), FeO(OH)·nH2O

Geode (unopened) or Calcareous Nodule

Siliceous or Calcareous Concretion/Nodule

Chert (White/Gray variety)

Silicon Dioxide (SiO2 / Cryptocrystalline Quartz)

Banded Chert

Silicon Dioxide (SiO2)

Chert (Common Opal or Chalcedony)

Microcrystalline Quartz (SiO2)

Chert (Siltstone-Chert mixture)

Microcrystalline Quartz (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Crinoid Fossil in Limestone

Crinoidea fossil (stalk segments) in Calcium Carbonate (CaCO3) matrix

Chert Nodules in Limestone

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Brown Chert

Microcrystalline Quartz (SiO2)