Sedimentary (Chemically Precipitated)

Banded iron formation fragment

BIF: microcrystalline quartz (chert/jasper) with iron oxides and/or magnetite

Chert Nodule

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Tufa

Calcium carbonate (CaCO3) - Porous Limestone

Banded Iron Formation (BIF)

Magnetite-hematite-chert formation

Honey Calcite

Calcite (Calcium Carbonate, CaCO3)

Hematite

Iron(III) oxide (Fe2O3)

Chert with Jasper/Quartz Inclusions

Silicon Dioxide (SiO2)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Pyrite-bearing sulfide specimen

Pyrite (FeS₂), possibly with chalcopyrite and quartz or carbonate gangue

Banded iron formation (BIF)

Banded iron formation; chiefly hematite/magnetite and microcrystalline quartz (chert)

Chert (with Quartz vein/coating)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Quartzite river pebble)

Microcrystalline Silica (SiO2)

Chert (White Variety)

Silicon Dioxide (SiO2)

Chert (Red Jasper)

Microcrystalline Quartz (SiO2)

Barite (Desert Diamond)

Barite (Barium Sulfate, BaSO4)

Jasper

Silicon Dioxide (SiO2), Microcrystalline Quartz

Banded iron formation fragment (likely hematite–magnetite ironstone)

Banded iron formation; chiefly hematite (Fe₂O₃), magnetite (Fe₃O₄), and microcrystalline quartz (SiO₂)

Ironstone Concretion (Limonite/Goethite)

Goethite-rich Concretion (FeO(OH))

Blue Calcite Sphere

Calcium Carbonate (CaCO3)

Pyrite with Limonite/Goethite Alteration (Pseudomorph)

Iron Sulfide (FeS2) transitioning to Hydrated Iron Oxides (FeO(OH)·nH2O)

Blue Calcite

Calcium Carbonate (CaCO3)

Celestite Geode

Strontium Sulfate (SrSO4)

Pyrite

Iron Sulfide (FeS2)

Jasper

Microcrystalline Quartz (SiO2)

Jasper in Quartz / Brecciated Jasper

Silicon Dioxide (SiO2) with iron oxide impurities

Quartz (Milky/Clear)

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Honey Calcite

Calcium Carbonate (CaCO3)

Agate

Chalcedony (Silicon Dioxide, SiO2)

Banded iron formation fragment (tumbled iron-rich rock)

Banded iron formation (BIF), chiefly hematite–magnetite with chert (SiO₂)

Chert

Microcrystalline Quartz (SiO2)

Banded iron formation pebble

Banded iron formation (BIF), chiefly hematite/magnetite with chert or jasper

Coquina

Biogenic Limestone (Coquina)

Hematite Nodular Iron Ore

Hematite (Fe2O3)

Pyrite

Iron Sulfide (FeS2)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Ferruginous Quartz on Ironstone

Silicon Dioxide (SiO2) with Hematite (Fe2O3)

Chert (Light Grey / Flint variant)

Cryptocrystalline Quartz (SiO2)

Calcite crystal cluster

Calcite, calcium carbonate (CaCO₃)