Sedimentary (Microcrystalline Silicate)

Coal (Bituminous)

Sedimentary carbonaceous rock

Ceramic or Polished Stone Heart (Anthropogenic Material)

Glazed Ceramic (Silicon Dioxide based coating on Alumina Silicate body) or Polished Limestone/Marble (Calcium Carbonate, CaCO3)

Greenstone / Metagraywacke

Metamorphosed basaltic or sedimentary rock (Complex Silicate)

Granite

Intrusive Igneous Rock

Likely weathered limestone or calcite-rich stone

Limestone, primarily calcium carbonate (CaCO₃), possibly calcite

Basalt Pebble

Basalt

Gneiss (High-grade Metamorphic Rock)

Gneiss (Metamorphic silicate rock)

Banded Gneiss

Gneiss (Metamorphic silicate rock)

Bauxite

Bauxite (Aluminum Ore)

Quartz Pebble with Chlorite or Epidote Inclusions

Silicon Dioxide (SiO2) with inclusions

Banded Chert / Jasper

Silicon Dioxide (SiO2)

Gneiss (specifically a weathered Amphibolite or Garnet Gneiss)

Gneiss (complex silicate composition)

Glauconitic Sandstone

Glauconitic Sandstone (Greensand)

Sandstone (likely Graywacke or Lithic Arenite)

Clastic sedimentary rock predominantly composed of silicate grains

Bauxite

Bauxite (Al(OH)3, AlO(OH))

Quartz Pebble

Silicon Dioxide (SiO2)

Oolitic Limestone / Fossiliferous Chert

Oolitic Limestone (CaCO3) / Silicified Limestone

Gneiss

Gneiss (foliated metamorphic rock)

Terracotta (Man-made ceramic brick fragment)

Baked clay / High-iron ceramic (Silicate-based ceramic)

Tumbled jasper (likely brecciated or iron-rich jasper)

Microcrystalline quartz/chalcedony, SiO₂, colored by iron oxides and possibly other silicates

Beryl (likely Pink/Morganite variety)

Beryllium aluminum silicate (Be3Al2Si6O18)

Chrysocolla in Quartz (Gem Silica)

Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla) / SiO2 (Quartz)

Zircon

Zircon (Zirconium Silicate, ZrSiO4)

Likely weathered gneiss or granite fragment

Quartz–feldspar–mica aggregate; probably granitoid gneiss, identification uncertain from the photograph

Chert (Green)

Silicon Dioxide (SiO2)

Mixed pebble collection, including likely flint, quartzite, and fossil material

Varied silicate rocks; visible specimen may include chert (microcrystalline SiO₂), quartzite, and a possible fossil

Bauxite

Aluminium ore / Hydrated aluminium oxides (AlOx(OH)3-2x)

Pyrite with Quartz

Iron Sulfide (FeS2) with Silicon Dioxide (SiO2)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Chrysoprase

Silicon Dioxide (Chalcedony variety), SiO2

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Quartz

Silicon Dioxide (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Glauconitic Sandstone

Greensand (Glauconite-bearing sandstone)

Yellow calcite fragment

Calcite (CaCO₃), likely honey/yellow calcite

Sandstone

Arenite

Yellow Jasper

Silicon Dioxide (SiO2) with Goethite/Iron Oxide inclusions

Shale

Lutaceous Rock (Hydrous Aluminum Silicates)

Quartzite

Quartzite (SiO2)

Green Opal

Hydrated amorphous silica (SiO2·nH2O)

Picture Jasper

Silicon Dioxide (SiO2) - Opaque cryptocrystalline variety of Quartz

Biotite Schist

Biotite Mica Schist [K(Mg,Fe)3AlSi3O10(OH,F)2]