Man Made (Synthetic Rock)

Chert

Chert (Microcrystalline Silica, SiO2)

Biotite Schist

Biotite Schist (Rich in K(Mg,Fe)3AlSi3O10(OH)2)

Gneiss

High-grade Metamorphic Gneiss

Sandstone (with potential fossil fragments)

Sandstone (SiO2 dominated with iron oxides)

Sandstone (likely Graywacke or Lithic Sandstone)

Clastic Sedimentary Rock

Granite

Intrusive igneous felsic rock

Conglomerate (Greenstone/Pebble Conglomerate)

Polymictic Conglomerate

Granodiorite (River Rock / Cobble)

Granodiorite; Phaneritic intrusive igneous rock dominated by plagioclase, quartz, and hornblende/biotite

Weathered granitic rock fragment

Granite, predominantly quartz–feldspar–mica assemblage

Brown Sandstone (River Rock)

Arenite

Quartz Pebble

Silicon Dioxide (SiO2)

Granite

Granite (Phaneritic igneous rock)

Granite

Phaneritic Igneous Rock (Granite)

Granite

Granite (Felsic Plutonic Rock)

Gneiss (with Quartz Vein / Pegmatite Banding)

Metamorphic Gneiss

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Granite

Felsic intrusive igneous rock

Granite

Felsic intrusive igneous rock

Granite

Intrusive Igneous Rock (composed primarily of quartz, alkali feldspar, and plagioclase)

Granite

Granite (Felsic intrusive igneous rock)

Granite

Felsic intrusive igneous rock

Granite

Felsic intrusive igneous rock

Granite

Felsic intrusive igneous rock

Serpentine

Serpentinite (Mg,Fe,Ni,Al,Zn)3Si2O5(OH)4

Sandstone or Siltstone

Arenite (if sandstone)

Basalt

Extrusive Igneous Rock

Basalt

Mafic Igneous Rock

Sandstone (with Siltstone/Greywacke variations)

Sedimentary Rock (Clastic)

Biotite Mica Schist

Metamorphic Rock containing Biotite K(Mg,Fe)3AlSi3O10(OH)2

Sandstone

Arenite (Siliclastic sedimentary rock)

Basalt

Extrusive Igneous Rock

Quartz with Host Rock

SiO2 (Quartz) with fine-grained Matrix

Shale

Lutaceous sedimentary rock

Mica schist, likely biotite–muscovite schist

Mica schist; predominantly quartz, feldspar, biotite and/or muscovite mica. Exact mineral composition cannot be confirmed from the photograph alone.

Limestone and Quartz Gravel with Petrified Wood

Sedimentary gravel aggregate and fossilized wood

Sandstone (Ferruginous)

Sandstone (SiO2 with iron oxide impurities)

Sandstone Pebble

Sedimentary quartz arenite

Tumbled Quartz

Silicon Dioxide (SiO2)

Sandstone Concretion

Sedimentary Concretion (Quartz sand bound by mineral cement)

Sandstone Pebble

Sedimentary Rock (Quartzose Sandstone)

Mixed Mineral Assortment (Pyrite, Kyanite, Agate, Jasper)

FeS2 (Pyrite), Al2SiO5 (Kyanite), SiO2 (Agate/Jasper)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)