Industrial Byproduct (Anthropogenic Rock Like Material)

Sandstone

Clastic sedimentary rock (quartz arenite)

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

Calcite (Calcium Carbonate, CaCO3)

Coquina

Biogenic Limestone (Calcium Carbonate, CaCO3)

Chert (Chalcedony/Agate variety)

Microcrystalline Quartz (SiO2)

Serpentinite

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

Limestone with Calcite

Sedimentary Calcium Carbonate (CaCO3)

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

White Marble

Recrystallized Calcite Rock (CaCO3)

Diamond

Carbon (C)

Limestone

Calcareous sedimentary rock (CaCO3)

Chert (potentially Fossiliferous or Jasperoid)

Microcrystalline Quartz (SiO2)

Asphalt (Bituminous pavement fragment)

Artificial conglomerate / Bitumen-Aggregate mixture

Basalt with Magnetite inclusions

Basalt (Mafic silicate rock) potentially containing Magnetite (Fe3O4)

Petrified Wood

Silicified Wood (Silicon Dioxide - SiO2)

Basalt

Extrusive mafic igneous rock

Sandstone

Arenite

Chert / Flint

Microcrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (Permineralized organic matter, głównie $SiO_2$)

Chert (Flint / Chalcedony variety)

Microcrystalline Quartz (SiO2)

Quartzite River Rock

Metamorphic Quartzite (primarily SiO2)

Chert (Jasper)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Anthracite Coal

Anthracite (Carbon-based sedimentary-metamorphic rock)

Ferruginous Sandstone

Arenite with Iron-Oxide cement (primarily Fe2O3 • nH2O)

Anthracite Coal

Anthracite (Carbon-based metamorphic rock)

Sandstone (Pebble)

Arenite (primarily SiO2)

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Sandstone

Arenite (primarily SiO2)

Quartz Geode

Crystalline Silicon Dioxide (SiO2) in a Geode

Chert (with Quartz veins)

Microcrystalline Quartz (SiO2)

Snowflake Obsidian

Spherulitic Volcanic Glass (primarily SiO2)

Quartz Druzy (Geode Fragment)

Silicon Dioxide (SiO2)

Gneiss

Gneiss

Basalt

Basalt (principally Plagioclase and Pyroxene)

Sandstone (Ferruginous)

Arenite with Iron Oxide (Fe2O3) cement

Coquina

Bioclastic Limestone

Grey Chert River Pebble

Microcrystalline Quartz (SiO2)

Conglomerate

Conglomerate (clastic sedimentary rock)

Sandstone with Trace Fossils

Quartz Arenite with Bioturbation (Trace Fossils)

Quartzite / Sandstone / Chert Mix

Silicon Dioxide (SiO2)

Sandstone

Arenite

Artificial Rock Face (Faux Rock)

Glass Fiber Reinforced Concrete (GFRC)