Man Made Rock (Sedimentary Analogue)

Anthracite Coal

Anthracite (Carbon C)

Greywacke (River Slikkenstone)

Greywacke (Impure Sandstone)

Gneiss

Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Mica/Amphibole)

Chert (specifically Gray/Tan Bedded Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartz

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Sandstone

Arenite (specifically Iron-stained Quartz Sandstone)

Sedimentary Sandstone (Sandstone Slab)

Arenite (SiO2 with Fe2O3 staining)

Sandstone (Quartzose Sandstone)

Arenite (composed primarily of SiO2)

Sandstone

Arenite

Chert (Jasper/Agate variety)

Silicon Dioxide (SiO2)

Quartz Geode

Crystalline Silicon Dioxide (SiO2) in Geode form

Chert (often called Jasper or River Siltstone)

Microcrystalline Quartz (SiO2)

Red Jasper

Chalcedony (SiO2 with iron oxide impurities)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Yellow Jasper

Silicon Dioxide (SiO2) with Goethite/Iron oxide inclusions

Quartzite

Quartzite (SiO2)

Sandstone with Ironstone Banding

Clastic Sandstone (composed of Quartz with Hematite/Limonite bonding)

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 cement)

White Agate (Chalcedony)

Silicon Dioxide (SiO2)

Gneiss

Gneiss (High-grade Metamorphic Rock)

Carnelian Agate

Carnelian (SiO2 with iron oxide impurities)

Petrified Wood

Silicified Wood (primarily Quartz / Chalcedony: SiO2)

Schist (Micaceous Schist)

Schist (comprising Muscovite/Biotite mica, Quartz, and Feldspar)

Yellow Quartzite or Yellow Jasper

Quartzite (primarily SiO2 with Iron oxide staining)

Sandstone

Arenite (SiO2 based)

Red Chert

Microcrystalline Quartz (SiO2)

Concretion or Geode (unbroken)

Varied (depending on mineral composition and cementing agent). For quartz-lined geodes, the scientific name of the dominant mineral would be Quartz (SiO2). For calcite-lined geodes, Calcite (CaCO3). Concretions are often composed of cryptocrystalline quartz (chert), calcite, or iron oxides.

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Ammonite Fossil

Ammonoidea (typically preserved as Calcite or Aragonite)

Chert (Jasper/Mudstone variety with Oxidation)

Silicon dioxide (SiO2)

Sandstone

Arenite (SiO2 based)

Flower Jasper

Agatized Fossil Coral / Chalcedony (SiO2)

Fossilized Turritella Gastropod (Internal Mold)

Turritella (Fossil Gastropod Crust)

Greywacke (River Siltstone)

Lithic Sandstone / Greywacke

Bauxite

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

Crinaudite / Fossilized Crinoid Stem

Crinoid (Echinodermata) in a Calcitic/Siliceous Matrix

Chalcedony in Host Rock

Silicon Dioxide (SiO2)

Magnetite Orthorthotropic Rock

Magnetite (Fe3O4)

Chalcedony on Matrix

Silicon Dioxide (SiO2)

Zebra Jasper

Silicon dioxide (SiO2) with various impurities

Gneiss

Gneiss (High-grade regional metamorphic rock)