Industrial Byproduct (Anthropogenic Rock Like Material)

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals, Mg3Si2O5(OH)4)

Quartzite

Metamorphic Quartz-rich Rock

Diorite

Intermediate Phaneritic Plutonic Rock - Diorite

Sandstone

Arenite (primarily SiO2 with various cementing agents)

Bauxite / Iron-rich Laterite

Laterite (principally Al(OH)3, Fe2O3, and SiO2)

Weathered fossiliferous limestone fragment, possibly fossil coral or shell material

Indeterminate carbonate fossil in calcitic limestone; likely composed mainly of calcite (CaCO₃), but species identification is not possible from this image alone

Sandstone (lithic/arkosic)

Clastic sedimentary rock (primarily SiO2)

Sandstone

Arenite (primarily SiO2)

Banded Sandstone

Quartz Arenite (with iron oxide banding)

Ferruginous Sandstone (Ironstone)

Sedimentary rock with Limonite/Goethite cement

Breccia

Breccia - Clastic sedimentary rock

Gneiss

Gneiss (quartz-feldspar-biotite gneiss)

Sandstone (Banded)

Clastic Sedimentary Rock (primarily Quartz, SiO2)

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)

Basalt

Mafic volcanic rock (various silicate minerals)

Quartz

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Anthracite Coal

Anthracite (Carbon-rich metamorphic rock)

Chert (Jasper)

Silicon Dioxide (SiO2)

Diamond (in jewelry setting)

Carbon (C)

Rough Diamond

Diamond (pure Carbon, C)

Garnet Schist

Almandine Garnet in Mica Schist (Fe3Al2(SiO4)3)

River Cobble (likely Serpentinite or Greenstone)

Serpentinite / Greenschist facies rock

Sandstone

Sandstone (SiO2 dominant)

Prehnite

Prehnite (Ca2Al2Si3O10(OH)2)

Sandstone

Arenite (SiO2 based)

Granite Cobble

Phaneritic Felsic Intrusive Rock (Granite)

Milky Quartz with Matrix

Silicon Dioxide (SiO2)

Sandstone (likely Graywacke or Arkose)

Arenite

Chert (Black Flint)

Silicon Dioxide (SiO2)

Basalt

Basalt (principally composed of pyroxene and plagioclase feldspar)

Sandstone

Arenite (SiO2 dominated sandstone)

Bauxite

Bauxite (Al(OH)3 mixed with Fe2O3 and clay minerals)

Sandstone (with Chert/Quartzite)

Arenite (SiO2 primarily)

Garnet-Bearing Schist

Almandine Garnet Micaceous Schist

Quartz Geode

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Arenite with Iron Oxide cement (SiO2 + Fe2O3)

Quartz with Chlorite / Greenschist

Quartz vein in Greenschist (SiO2 with Chlorite group minerals)

Sandstone (Ferruginous)

Arenite (Fe2O3 enriched)

Quartz Pebble (Geode-like)

Silicon Dioxide (SiO2)

Quartzite

Quartzite

River Pebble (Quartz-rich)

Silicon Dioxide (SiO2) with various inclusions