Mineral, Often Found As Detrital Grains In Sedimentary Rocks

Agate (specifically Chalcedony nodule)

Silicon Dioxide (SiO2)

Quartzite with inclusions

Quartzite (primarily SiO2)

Bauxite

Bauxite (Mixture of Al(OH)3, AlO(OH), and Fe2O3)

Grey Chalcedony (Tumbled)

Chalcedony (SiO2)

Gneiss

Gneiss

Chert (Chalcedony/Agate)

Microcrystalline Quartz (SiO2)

Epidote-bearing Granite (Unakite-like)

Epidotized Granite

Red Sandstone

Arenite (with Iron Oxide cement)

River Rock

Sedimentary Rock (various compositions)

Sandstone (Ferruginous)

Arenite (Fe-rich SiO2)

River Stone (likely Siltstone or fine-grained Sandstone)

Clastic Sedimentary Rock (Lithic Wacke / Siltstone)

Shale

Fissile mudstone (rich in clay minerals and quartz)

Sandstone

Sandstone (clastic sedimentary rock, composed predominantly of sand-sized minerals or rock fragments)

Sandstone (likely Quartzose Sandstone)

Arenite (SiO2 principal composition)

White Agate / Chalcedony

Silicon Dioxide (SiO2)

Shale

Laminated Mudstone

Sandstone Pebble

Arenite (primarily SiO2)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Shale

Fissile Mudstone

Sandstone (Painted)

Arenite (primarily SiO2)

Ironstone Concretion (Moqui Marble type)

Ferruginous Concretion (Fe2O3 / FeO(OH))

Ironstone Concretion (Limonite/Goethite)

Ferruginous Sandstone or Limonite (FeO(OH)·nH2O)

Sandstone (Quartzose Sandstone)

Arenite (primarily SiO2)

Sandstone (Ferruginous)

Arenite (iron-rich)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Chalcedony (Moonstone-like Agate)

Silicon Dioxide (SiO₂)

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement

Sandstone

Arenite

Sandstone

Clastic Sedimentary Rock (composed primarily of Quartz: SiO2)

Ferruginous Sandstone

Arenite with Iron-oxide cement (composed of Quartz and Limonite/Hematite)

Quartz

Quartz (SiO2 - Silicon Dioxide)

Sandstone

Arenite (composed primarily of SiO2)

Schist

Mica Schist (Variable chemistry, often rich in muscovite and biotite)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Red Sandstone

Arenite (Ferruginous Sandstone)

Sandstone (likely Calcareous or Micaceous)

Clastic sedimentary rock (primarily Quartz with Cementing Agents)

Red Sandstone

Clastic Sedimentary Mineraloid (predominantly Quartz grains with Iron Oxide cement)

Sandstone (Ferruginous)

Arenite with Iron oxide staining (SiO2 with Fe2O3)

Shale

Lutaceous Sedimentary Rock

Sandstone

Arenite (primarily SiO2)

Sandstone

Arenite (primarily SiO2)