Sedimentary Rock (Technically A Variety Of Chalcedony)

Sandstone

Arenite (composed primarily of SiO2)

River Stone (likely Siltstone or fine-grained Sandstone)

Clastic Sedimentary Rock (Lithic Wacke / Siltstone)

River Stone / Pebble

Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)

Serpentinite

Serpentinite (composed primarily of Serpentine minerals: Mg3Si2O5(OH)4)

Gneiss (Metamorphic Rock)

Gneiss (variable mineral formula primarily containing Quartz, Feldspar, and Mica)

Druzzy Quartz on Matrix

Silicon Dioxide (SiO2)

K2 Azurite Granite / K2 Stone

Granite (igneous rock) with Azurite inclusions (mineral)

Petrified Wood

Silicified wood (Quartz/Chalcedony/Opal replacing organic matter)

Serpentine

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

Quartz (Milky/Smoky variety on matrix)

Silicon Dioxide (SiO2)

Ferruginous Sandstone (Gozzan/Ironstone)

Arenite with Limonite/Goethite cement (FeO(OH)·nH2O)

Shale with Iron Oxide Staining

Fissile Mudstone (primarily clay minerals and quartz)

Green Jasper

Silicon Dioxide (SiO2) with impurities

Ferruginous Sandstone (Ironstone)

Clastic sedimentary rock (SiO2 with Fe2O3/FeO(OH) cement)

Yellow Calcite

Calcium Carbonate (CaCO3)

Sandstone (with Feldspathic/Arkose qualities)

Arenite (primarily SiO2 with KAlSi3O8 components)

Dalmatian Stone

Peralkaline Feldsphathic Igneous Rock

Sandstone (Ferruginous)

Sandstone (SiO2 with iron oxide inclusions)

Sandstone (Ferruginous)

Arenite (with Hematite/Limonite cement)

Sandstone with Magnetite and Iron Staining

Clastic Sedimentary Rock (contains Fe3O4 and Limonite/Hematite)

Pyrite in Quartz

Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)

River Jasper (Chert/Chalcedony)

Silicon Dioxide (SiO2) with iron oxide impurities

Sandstone

Arenite

Milky Quartz

Quartz (Silica / Silicon Dioxide), SiO2

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Ferruginous Chert

Silicon dioxide with iron oxide impurities (SiO2 + Fe2O3)

Basalt with Magnetite inclusions

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

Ferruginous Sandstone

Arenite with Iron-Oxide Cement (SiO2 with Fe2O3/FeO(OH))

Chert (Jasper/Opaline variety)

Silicon Dioxide (SiO2)

Diorite

Phaneritic Intrusive Igneous Rock (composed of Plagioclase feldspar, Hornblende, and Biotite)

Black Opal

Hydrated Silica (SiO2·nH2O)

Quartz

Quartz (SiO₂)

Goethite (Iron Ore)

Goethite (FeO(OH))

Gneiss

Gneiss

Rose Quartz

Quartz (SiO₂), specifically a variety of Quartz

Sandstone

Clastic Sedimentary Rock (composed of SiO2 grains)

Sandstone (specifically Red Sandstone)

Arenite (primarily Quartz, SiO2)

Serpentine

Antigorite / Lizardite / Chrysotile [(Mg,Fe)3Si2O5(OH)4]

Halite

Halite (Sodium Chloride, NaCl)

Schist with Schorl (Black Tourmaline)

NaFe3Al6(BO3)3Si6O18(OH)4 (Schorl)

Geode (unopened)

SiO2 - Chert-shelled concretion (mostly Quartz)

Chert (often called Flint)

Chert (Microcrystalline or cryptocrystalline Silica, SiO2)