Sedimentary Mineral

Magnetite

Iron(II,III) oxide (Fe3O4)

Hematite Ball

Iron(III) oxide (Fe2O3)

Pyrite

Iron Disulfide (FeS2)

Botryoidal Quartz

Silicon Dioxide (SiO2)

Dendritic Agate or Manganese Nodule in Chert/Limestone

Silicon Dioxide (SiO2) with Manganese Oxide (MnO2) inclusions

Sandstone (Iron-stained)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)

Sandstone

Sandstone (clastic sedimentary rock)

Weathered sandstone or arkosic sandstone

Clastic sandstone, likely quartz–feldspar-rich (arkose)

Hematite

Iron(III) oxide (Fe2O3)

Sandstone with Iron Staining

Arenite (SiO2 with FeO(OH) impurities)

Hematite

Iron(III) oxide (Fe2O3)

Botryoidal Pyrite

Iron Sulfide (FeS2)

Foliated Metamorphic Rock (likely Gneiss or Schist)

Gneissic Metamorphic Rock

Sedimentary Breccia

Breccia (Clastic Sedimentary Rock)

Weathered conglomeratic rock, likely iron-stained sandstone

Probable ferruginous, clast-bearing sandstone; exact identification requires examination of a fresh surface

Mixed Mineral Collection

Multi-mineral Assemblage (Quartz, Jasper, Obsidian, Pyrite, etc.)

Painted River Rock

Artificially Coated Sedimentary Rock

Sandstone

Clastic sedimentary rock (primarily Quartz)

Likely mica schist

Mica-rich schist, probably biotite–quartz–feldspar schist

Sandstone Pebble

Sedimentary Rock (Quartzose Sandstone)

Banded gneiss

Gneiss, commonly quartz–feldspar–mica gneiss

Brown Chalcedony

Silicon Dioxide (SiO2)

Quartz (Rose Quartz or Chert variant)

Silicon Dioxide (SiO2)

Quartz (Agate/Jasper pebble)

Silicon Dioxide (SiO2)

Banded Agate with Drusy Quartz

Cryptocrystalline Quartz (SiO2) with macrocrystalline Quartz

Sandstone (with ripple marks)

Arenite / Quartz Sandstone

Ironstone (Limonite/Hematite)

Ferruginous sedimentary rock (Fe2O3·nH2O / Fe2O3)

Pyrite in Matrix (Fool's Gold)

Iron Sulfide (FeS2)

Exposed shoreline bedrock and sediment

Unidentified natural rock; the image does not show enough detail for a specific geological identification

Quartz with Calcite / Geode Fragment

Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3)

Tumbled brecciated jasper

Silica-rich microcrystalline quartz/chalcedony (SiO₂), with iron-oxide and other mineral inclusions

Gossanous Sandstone (likely Terrestrial)

Arenite with Iron-Oxide inclusions

Sandstone (likely Arkosic or Lithic Sandstone)

Clastic Sedimentary Rock (SiO2 with assorted minerals)

Sandstone (Weathered Pebble)

Sedimentary Rock (Quartz arenite)

Sandstone

Sedimentary Rock (Quartz Sandstone)

Sandstone

Sedimentary Rock (Quartz arenite)

Sandstone

Arenite (Clastic Sedimentary Rock)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Sandstone (Weathered / Crushed)

Quartz Sandstone

Quartz-veined Sandstone Pebble

Quartzite-veined Arenite

Sandstone

Clastic Sedimentary Rock

Rhodochrosite

Rhodochrosite (MnCO3)