Man Made Rock (Technosol)

Quartzite (River Cobble)

SiO2 (Quartz-rich Metamorphic Rock)

Basalt with Quartz Veining

Basalt (Mafic Volcanic Rock with SiO2)

Granite

Granite (Phaneritic intrusive igneous rock)

Tiger's Eye (Rough)

Pseudomorph of Quartz after Crocidolite (SiO2 with FeOOH inclusions)

Limonite-stained Quartz

Silicon Dioxide (SiO2) with Iron Oxide/Hydroxide (FeO(OH)·nH2O) staining

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Iron-Stained Quartz (Riverside Cobble)

Silicon Dioxide (SiO2) with Limonite/Hematite inclusions

Andesite

Andesite (Intermediate Extrusive Volcanic Rock)

Sandstone (Ferruginous)

Sandstone (Clastic sedimentary rock, predominantly SiO2 with Fe2O3 cement)

Gneiss Pebble

Gneiss

Yellow Quartzite

Quartzite (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Basalt

Basalt (Aphanitic Mafic Volcanic Rock)

Basalt (Porphyritic Basalt)

Porphyritic Basalt (Mafic volcanic rock)

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Basalt

Vesicular Basalt (Mafic volcanic rock)

Scoria (Red Lava Rock)

Scoria

Travertine

Terrestrial Sedimentary Rock (Calcium Carbonate, CaCO3)

Sandstone

Arenite (primarily SiO2)

Quartzite (River Pebble)

Recrystallized Quartz (SiO2)

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartzite Pebble

Quartzite (primarily SiO2)

Quartz (Milky Quartz / Quartzite)

Silicon Dioxide (SiO2)

Scoria (Lava Rock)

Aphanitic vesicular mafic igneous rock

Conglomerate (River Rock)

Clastic sedimentary rock (primarily SiO2)

Scoria (Lava Rock)

Scoria (Vesicular Basaltic Glass/Rock)

Gemstone Sand (Mineral Assortment)

Mixed Mineral Concentrates (Commonly including Quartz SiO2, Garnet X3Y2(SiO4)3, and Tourmaline (Na,Ca)(Li,Mg,Al)3(Al,Fe,Mn)6(BO3)3(Si6O18)(OH,F)4)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Pink Quartzite

Quartzite (mainly SiO2 with iron oxide impurities)

Sandstone (specifically an Iron-Concretion)

Arenite with Iron Oxide (Limonite/Goethite) cementation

Basalt

Basalt (Composition primarily Plagioclase feldspar, Pyroxene, and Olivine)

Gneiss

Gneiss (High-grade metamorphic rock)

Granite

Phaneritic intrusive igneous rock (composed mainly of Quartz SiO2, Feldspar KAlSi3O8, and Biotite/Mica)

Red Sandstone (Old Red Sandstone)

Ferruginous Sandstone (SiO2 + Fe2O3)

Sandstone (Quartzite-rich River Cobble)

Clastic sedimentary rock (primarily SiO2)

Sandstone (likely with Quartz Veining)

Arenite (primarily SiO2)

Fossilized Coral

Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)

Basalt Arrowhead (worked stone)

Aphanitic mafic volcanic rock (Basalt)

Granodiorite

Granodiorite (calc-alkaline phaneritic igneous rock)

Quartz with Mica Schist (Pegmatite Specimen)

SiO2 (Silicon Dioxide) and Phyllosilicates (Biotite/Muscovite)