Sedimentary (Chemically Precipitated)

Likely limestone

Calcite-rich carbonate rock; mainly calcium carbonate (CaCO₃)

Weathered banded iron formation (iron-rich quartzite)

Banded iron formation (BIF), chiefly hematite/magnetite and microcrystalline quartz (SiO₂)

Chert (Arrowhead or Flake)

Microcrystalline quartz (SiO2)

Chert (with Quartz Veining)

Microcrystalline Quartz (SiO2)

Orange Calcite

Calcite (Calcium Carbonate, CaCO3)

Barite Rose

Barium Sulfate (BaSO4)

Honey calcite (likely)

Calcite, calcium carbonate (CaCO₃)

Sandstone with Liesegang Rings

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

Weathered limestone boulder

Limestone, composed mainly of calcite (CaCO₃); exact identification cannot be confirmed from the image alone.

Weathered porous limestone

Calcite-rich limestone (CaCO₃), possibly fossiliferous or dolomitic

Banded iron formation (ironstone), possibly jasper–hematite

Banded iron formation; chiefly hematite (Fe₂O₃), magnetite (Fe₃O₄), and silica (microcrystalline quartz/chert)

Green Chert

Silicon Dioxide (SiO2)

Chert (Flint) with Limonite Staining

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Silicon dioxide (SiO2)

Banded Chert Pebble

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Oolitic Limestone (Egg Stone)

Oolite (Chemical sedimentary rock, primarily CaCO3)

Red jasper (likely iron-rich chert)

Microcrystalline quartz (SiO₂) colored by hematite/goethite; possibly ferruginous chert

Quartz

Silicon Dioxide (SiO2)

Flint / Chert Pebble

Microcrystalline Quartz (SiO2)

Banded Iron Formation

Banded Iron Formation (BIF), typically composed of magnetite, hematite, and chert

Quartz Druzy in Chert Pebble

Silicon Dioxide (SiO2) - Microcrystalline & Crystalline Quartz

Jasper

Silicon Dioxide (Microcrystalline Quartz, SiO2)

Quartz (Milky/Chalcedony variety)

Silicon Dioxide (SiO2)

Jasper Pebble

SiO2 (Microcrystalline Quartz)

Jasper

Silicon dioxide (Microcrystalline quartz, SiO2)

Pyrite

Iron Sulfide (FeS2)

Orange Calcite

Calcium Carbonate (CaCO3)

Quartz (Raw Chunk)

Silicon Dioxide (SiO2)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2)

Chert (Septarian Nodules-like)

Silicon dioxide (SiO2)

Chert pebble

Microcrystalline silica (SiO2)

Chert (Flint)

Chert (Cryptocrystalline Quartz, SiO2)

Quartz

Silicon Dioxide (SiO2)

Chert

Microcrystalline silica (SiO2)

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)