Sedimentary Rock (Possibly A Conglomerate Or Coarse Grained Sandstone)

Weathered quartz-rich metamorphic rock, likely quartzite

Quartzite (mostly microcrystalline SiO₂), possibly iron-stained mica-bearing quartzite

Shale (sub-type: Carbonaceous Shale)

Lutaceous Sedimentary Rock

Sandstone (likely Siltstone or fine-grained Sandstone)

Sedimentary Rock (Clastic)

Sandstone (Limonitic/Iron-stained)

Sandstone (containing Quartz, SiO2, and Limonite, FeO(OH)·nH2O)

Sandstone

Sedimentary Rock (Quartz Sandstone)

Sandstone

Arenite (primarily SiO2)

Iron-rich weathered stone, possibly limonite/goethite

Limonite (mixture of hydrated iron oxides), commonly goethite (α-FeO(OH))

Fossiliferous Shale or Slate with Plant Fossils

Fossil-bearing argillaceous rock

Sandstone (Ferruginous)

Arenite (Fe-rich)

Coarse-grained gray metamorphic rock, likely gneiss

Biotite–quartz–feldspar gneiss (probable)

Sandstone Pebble

Sedimentary Rock (Quartzose Sandstone)

Sandstone

Arenite (primarily SiO2)

Rounded sandstone pebble

Quartz-rich sandstone (likely arkosic or lithic sandstone)

Sandstone (Quartzose Sandstone)

Arenite (primarily SiO2)

Sandstone

Arenite

Sandstone

Arenite (SiO2 principal)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 cement)

Sandstone

Arenite

Banded Gneiss (with possible weathered sulfide or iron staining)

Gneiss, potentially with iron oxide/hydroxide staining (e.g., limonite) or weathered sulfides

Sandstone

Arenite

Sandstone

Arenite

Sandstone (Quartzose)

Arenite (primarily SiO2)

Sandstone (Pebble)

Arenite

Weathered iron-stained quartzite or sandstone cobble

Quartzite (quartz-rich rock), possibly ferruginous sandstone

Sandstone

Sandstone (clastic sedimentary rock)

Quartzite Sandstone / Quartz Sandstone

Quartz Sandstone (SiO2 with minor mineral impurities)

Sandstone

Sandstone (Sedimentary rock composed of silicate grains)

Sandstone

Quartzose Sandstone (Sedimentary Rock)

Tumbled brown stone, likely jasper or fine-grained quartzite

Uncertain; probable microcrystalline quartz (SiO₂), possibly ferruginous jasper

Coarse-grained granite or granitic gneiss

Granite (quartz–feldspar–mica aggregate), possibly gneiss if foliation is present

Unknown Rock Specimen

Gneiss

Gneiss (High-grade regional metamorphic rock)

Sandstone

Arenite (Sedimentary rock)

Sandstone (Quartz-rich)

Arenite

Sandstone (likely Quartzose)

Clastic sedimentary rock (SiO2 primary)

Sandstone (likely Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Siltstone

Siltstone (primarily SiO2, Al2O3)

Limestone

Calcium carbonate (CaCO3)

Sandstone (likely Graywacke or Lithic Sandstone)

Clastic Sedimentary Rock

Sandstone (specifically Flagstone)

Arenite (primarily composed of SiO2)

Sandstone

Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)