Not A Rock (Man Made Origin)

Sandstone

Arenite (primarily composed of SiO2 - Silicon Dioxide)

Basalt (Weathered Pebble)

Extrusive mafic rock (primarily Plagioclase Feldspar and Pyroxene)

Sandstone (Ferruginous)

Sandstone (primarily SiO2 with Iron Oxide cement)

Sandstone (Quartz-rich)

Arenite (composed mainly of SiO2)

Sandstone

Arenite (Clastic Sedimentary Rock)

Sandstone

Arenite (SiO2 based)

Basalt

Basalt (containing Pyroxene, Plagioclase Feldspar, and Olivine)

Clear Quartz

Silicon Dioxide (SiO2)

Basalt (Water-worn pebble)

Mafic Igneous Rock (primarily Plagioclase feldspar and Pyroxene)

Granite

Granite (Felsic Plutonic Rock)

Basalt

Extrusive Mafic Igneous Rock

Basalt (Water-worn Pavement Stone)

Basalt (Mafic Extrusive Igneous Rock)

Granite

Granite (Mainly Quartz SiO2 and Feldspar KAlSi3O8)

Sandstone (Beach Pebble)

Clastic sedimentary rock (primarily Quartz and Feldspar)

Granite

Phaneritic Felsic Igneous Rock

Banded Calcite (often sold as 'Travertine' or 'Mexican Onyx')

Calcium Carbonate (CaCO3)

Sandstone

Arenite (Clastic Sedimentary Rock)

Basalt

Extrusive mafic igneous rock

Limestone

Calcium Carbonate (CaCO3)

Pink Feldspar

Orthoclase Feldspar (KAlSi3O8)

Quartz Vein on Matrix

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Sandstone

Arenite (primarily SiO2)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Dalmatian Stone

Peralkaline Quartz-Feldspar Rock

Schist

Mica Schist (primarily consisting of muscovite KAl2(AlSi3O10)(OH)2 or biotite K(Mg,Fe)3(AlSi3O10)(OH)2)

Basalt (Water-worn Pebble)

Basalt (Aphanitic Mafic Igneous Rock)

Sandstone

Arenite (SiO2 based)

Peridot in Basalt

Olivine ((Mg, Fe)2SiO4) in Basalt

Unakite

Epidotized Granite

Sandstone (Quartzose)

Arenite (composed mainly of SiO2)

Sandstone (with Concretion)

Arenite / Quartzose Sandstone

Sandstone (Quartzose)

Arenite (primarily SiO2)

Sandstone

Arenite (SiO2 based with primary clasts 0.0625 to 2 mm)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Sandstone (likely Greywacke variant)

Arenite

Wishing Stone (Basalt/Greywacke with Quartz Vein)

Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion

Serpentine

Serpentine-group ((Mg,Fe,Ni,Al,Zn,Mn)3(Si,Al,Fe)2O5(OH)4)

River/Stream Pebble

Clast / Detrital Grain / Rounded Sedimentary Particle (Compositionally variable, commonly Quartz, Feldspar, Chert, or other resistant rock fragments)

Quartz Geode

Silicon Dioxide (SiO2) in Host Rock