Synthetic (Not A Rock Or Mineral)

Limonitic Iron Ore / Goethite

Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz Druze on Matrix (Geode Fragment)

Quartz (Silicon Dioxide, SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Tiger's Eye (with Blue Tiger's Eye / Hawk's Eye)

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)

Turquoise

Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O

Red Sandstone (Hematitic)

Clastic sedimentary rock (SiO2 with Fe2O3 inclusions)

Tiffany Stone

Fluorite Opal (a complex mix of Fluorite, Opal, Calcite, Dolomite, Quartz, and Bertrandite)

White Chalcedony (likely Common Opal or Milky Quartz)

Silicon Dioxide (SiO2)

Quartz with Iron Oxide Monzonite or Sandstone contact

Quartz (SiO2) with Limonite/Hematite staining

Granite

Granite (compositionally: Quartz, Feldspar, Mica)

Sandstone (Quartzite-rich)

Clastic sedimentary rock (SiO2 primary)

Sandstone (with potential Arkose/Lithic characteristics)

Arenite (Sedimentary rock composed of sand-sized grains)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of iron oxide)

Pyrite (on Quartz/Host Rock)

Iron Sulfide (FeS₂)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Calcite Geode

Calcium Carbonate (CaCO3)

Vesicular Basalt (or Scoria)

Vesicular Basalt (Aphanitic-vesicular volcanic rock)

Gneiss

Gneiss

Biotite Mica in Host Rock

Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)

Sandstone (Graywacke type)

Clastic Sedimentary Rock (Lithic Sandstone)

Fossilized Bone Fragment

Permineralized Vertebrate Fossil (Hydroxyapatite replaced by Minerals)

Blue Dyed Agate Geode

Chalcedony (cryptocrystalline Quartz), SiO2

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Garnet Schist

Almandine Garnet-Mica Schist (X₃Y₂(SiO₄)₃)

Glauconitic Sandstone (Greensand)

Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2

Granite Pebble (River Rock)

Granite (composed primarily of Quartz, Feldspar, and Mica)

Dalmatian Stone

Peralkaline rhyolite with arfvedsonite (formerly incorrectly called Dalmatian Jasper)

Coarse Sand Grain / Lithic Fragment

Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)

Oolitic Chert

Silicon Dioxide (SiO2) with Oolitic texture

Sandstone Concretion

Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)

Quartz Pebble

Silicon Dioxide (SiO2)

Greenstone

Metamorphosed Mafic Igneous Rock

Sandstone (likely Quartzose Sandstone)

Arenite (SiO2 predominantly)

Amphibolite with Hornblende

Amphibole-rich Metamorphic Rock (Ca2(Mg,Fe)5Si8O22(OH)2)

Sandstone (specifically Lithic or Quartz Arenite)

Arenite (composed primarily of SiO2)

Goethite (Iron Ore)

Goethite (FeO(OH))

Red Sandstone Pebble

Arenite (primarily Quartz SiO2 with Hematite Fe2O3 staining)

Sandstone

Arenite (primarily SiO2)

Sandstone (likely Quartzose Sandstone)

Clastic Sedimentary Rock (primarily SiO2)