Rock

Granite

Felsic Plutonic Rock (Granite)

Sandstone (likely Quartz Sandstone)

Arenite (SiO2 based)

Milky Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Geode with Quartz/Chalcedony

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Scoria (Lava Rock)

Scoria

Scoria (Lava Rock)

Vesicular Basalt / Scoria

Schorl (Black Tourmaline) in Quartz or Feldspar Matrix

NaFe3Al6(BO3)3Si6O18(OH)4 (Schorl) in Granitic Pegmatite

Chert (Chert / Flint)

Silicon dioxide (SiO2) - Microcrystalline quartz

Sandstone Concretion

Arenaceous concretion (primarily SiO2 with Fe2O3 staining)

Milky Quartz (Water-worn Pebble)

Silicon Dioxide (SiO2)

Green Aventurine

Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2

Quartzite

Quartzite (SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2)

Orthoceras Fossil in Limestone

Orthoceras (extinct genus of cephalopods), mineralized as Calcite (CaCO3) in Fossiliferous Limestone

Chert (Nodule)

Silicon Dioxide (SiO2)

Pyrite in Shale

Iron Sulfide (FeS2) in Argillaceous Shale

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Quartzite Pebble

Quartzite (SiO2 with minor impurities)

Green Porphyry (Flowerstone)

Porphyritic Andesite or Basalt

Charoite

Charoite (Hydrated potassium sodium calcium barium strontium silicate hydroxyfluoride)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz / Quartzite

Silicon Dioxide (SiO2)

Azurite and Malachite on Matrix

Cu3(CO3)2(OH)2 (Azurite) and Cu2CO3(OH)2 (Malachite)

Ocean Jasper

Spherulitic Chalcedony (SiO2)

Stromatolite

Laminated biogenic sedimentary structure (formed by Cyanobacteria)

Citrine (Heat-treated Amethyst)

Citrine Quartz (SiO2)

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Copper Ore with Malachite and Chrysocolla

Cu2CO3(OH)2 (Malachite) with Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla)

Dyed Pink Agate

Silicon Dioxide (SiO2) - variety Chalcedony

Limestone with Calcite Veins

Sedimentary Calcium Carbonate (CaCO3)

Petrified Wood

Silicified wood (primarily Silicon Dioxide - SiO2)

Sandstone

Clastic Sedimentary Rock (composed mostly of quartz, SiO2)

Epidote in Matrix (Unakite-related)

Epidosite (Ca2(Al,Fe)3(SiO4)3(OH))

Shale (possibly)

Shale (fine-grained clastic sedimentary rock)

Chert

Chert (microcrystalline quartz, SiO2)

Basalt with Epidote (Porphyry)

Basalt (with inclusions of Epidote/Feldspar)

Granite

Granite (compositionally: Quartz, Feldspar, Mica)

Basalt with Mineral Vein (Cobble)

Basalt (with likely Quartz/Calcite vein)

Chert (Tan/Grey variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Carnelian (Chalcedony)

Cryptocrystalline Quartz (SiO2) with Iron Oxide impurities