Sedimentary Rock (Possibly Composed Of Various Minerals)

Quartz (specifically Clear Quartz or Rock Crystal)

Silicon Dioxide (SiO2)

Almandine Garnet in Schist

Almandine, Fe3Al2(SiO4)3

Ferruginous Sandstone

Sandstone with Iron Oxide (Limonite/Goethite)

Fossiliferous Chert with Brachiopod Impression

Chert (SiO2) containing Brachiopoda fossil remains

Quartz (Milk Quartz / Massive Quartz)

Silicon Dioxide (SiO2)

Amethyst

Silicon Dioxide (SiO2) with trace Iron impurities

Ironstone Concretion (Moqui Marble Type)

Goethite/Hematite-cemented Sandstone Concretion

Mica Schist

Crystalline Schist (often containing Muscovite, Biotite, and Quartz)

Hematite

Iron(III) oxide (Fe2O3)

Geode (unopened)

Calcedony-lined Geode (SiO2)

Sandstone (Ferruginous)

Arenite (Fe-rich)

Granite

Phaneritic Felsic Intrusive Igneous Rock

Wallboard/Drywall (Gypsum-based)

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Shale

Shale (composition varies: primarily clay minerals and quartz)

Gneiss (specifically a Granitic Gneiss)

Gneiss (Composition: Quartz, Feldspar, Mica)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Granite Pebble (River Rock)

Granite (composed primarily of Quartz, Feldspar, and Mica)

Sandstone (likely Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Pegmatite

Pegmatitic Granite

Slate

Slate (a fine-grained, foliated metamorphic rock). Mineral composition: Primarily composed of mica minerals (muscovite, chlorite, sericite) and quartz, with minor amounts of hematite, pyrite, and other accessory minerals.

Chert (specifically Tan/Brown Chert)

Chert (SiO2)

Gold-Bearing River Sand

Auriferous Placer Sand (Au + various minerals like SiO2 and Fe3O4)

Turquoise in Matrix

Hydrated phosphate of copper and aluminum (CuAl6(PO4)4(OH)8·4H2O)

Ferruginous Sandstone

Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)

Ironstone (Limonitic Concretion)

Limonite (FeO(OH)·nH2O) with Goethite and Hematite inclusions

Banded Gneiss (with Quartz Vein)

Gneiss (Metamorphic rock of varying mineralogy)

Limonite Concretion (Ironstone)

Limonite (FeO(OH)·nH2O) / Goethite

Shale

Shale (comprised mostly of clay minerals and quartz)

Clear Quartz

Silicon Dioxide (SiO2)

Bronzite

MgSiO3 (Enstatite with 10-30% FeSiO3 in solid solution)

Quartz (likely a clear or rock crystal variety)

Quartz (SiO2 - Silicon Dioxide)

Granite

Phaneritic Plutonic Felsic Rock

Conglomerate

Conglomerate rock

Ironstone Concretion (Boji Stone/Moqui Marble type)

Goethite/Hematite-encrusted Sandstone Concretion

Tree Agate

Dendritic Chalcedony (SiO2)

Schist (Micaceous Schist)

Schist (comprising Muscovite/Biotite mica, Quartz, and Feldspar)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Granite

Granite (a felsic intrusive igneous rock)

Milky Quartz

Silicon Dioxide (SiO2)

Gneiss

Gneiss (High-grade metamorphic rock)

Quartz with Chalcedony

Silicon dioxide (SiO2)