Not A Rock Or Mineral (Anthropogenic Material)

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

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)

Eclogite

Eclogite (Omphacite + Pyrope)

Turquoise, Pearl, and Coral Necklace

CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)

Milky Quartz with inclusions

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Travertine (used in construction, not a 'specimen' in situ)

Travertine

Quartz Geode (with possible Manganese or Goethite coating)

Silicon Dioxide (SiO2)

Turquoise

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

Blue Quartzite (Aventurine variety)

Silicon Dioxide (SiO2) with inclusions of Dumortierite or Magnesio-riebeckite

Bauxite

Bauxite (Al2O3·nH2O)

Limonite-stained Quartz

Silicon Dioxide (SiO2) with Iron Oxide/Hydroxide (FeO(OH)·nH2O) staining

Lapis Lazuli

Lapis Lazuli (A metamorphic rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Opalite (Synthetic Moonstone/Sea Opal)

Silicon Dioxide (SiO2) glass with metallic inclusions

Lapis Lazuli

Lapis Lazuli (Rock composed primarily of Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, Calcite, and Pyrite)

Petrified Wood

Silicified Wood (SiO2)

Limonite (Bog Iron)

Limonite (Hydrated iron(III) oxide-hydroxide) - FeO(OH)·nH2O

Sandstone

Arenite (composed mainly of SiO2)

Sandstone

Arenite (SiO2 predominantly)

Sandstone (likely Arkose)

Arenite (Feldspathic Sandstone / Arkose)

Petrified Wood

Silicified Wood (SiO2)

Quartz on Schist

Silicon Dioxide (SiO2) on Foliated Metamorphic Rock

Granite

Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Sandstone (lithic/greywacke variant)

Clastic sedimentary rock (primarily SiO2 with rock fragments)

Granite

Plutonic felsic igneous rock

Milky Quartz with Mineral Inclusions

Silicon Dioxide (SiO2) with miscellaneous inclusions

Basalt River Cobble

Basalt (Aphanitic Mafic Volcanic Rock)

Sandstone with Magnetite and Iron Staining

Clastic Sedimentary Rock (contains Fe3O4 and Limonite/Hematite)

Blue Chalcedony

Chalcedony (SiO2)

Diamond (or Cubic Zirconia simulant)

Carbon (C) or Zirconium Dioxide (ZrO2)

Coarse-grained Granite

Granitoid (KAlSi3O8 + SiO2 + NaAlSi3O8)

Petrified Wood

Silicified Wood (SiO2)

Quartz Geode

Quartz (Silicon Dioxide - SiO2) within a Chalcedony and Limonite shell

Olivine (Peridot)

Olivine Group (Magnesium Iron Silicate), (Mg, Fe)2SiO4

Rhodonite Tumbled Chips

Manganese silicate (Mn,Fe,Mg,Ca)SiO3

Green Calcite

Calcium Carbonate (CaCO3)

Quartz (Smoky or Impure Variety)

Silicon Dioxide (SiO2)

White Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Sodalite

Sodalite (Na8(Al6Si6O24)Cl2)

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Anyolite (Ruby in Zoisite)

Zoisite with inclusions of Hornblende and Ruby (Ca2Al3(SiO4)3(OH))

Amygdaloidal Basalt

Amygdaloidal Basalt containing Zeolite and Calcite inclusions