Mineral (Biogenic)

Emerald / Green Beryl

Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of Iron Oxide)

Yooperlite (Syenite clast containing fluorescent Sodalite)

Sodalite-bearing Syenite

Amazonite

Potassium Feldspar (KAlSi3O8) with lead impurities

Yellow Quartz (Citrine/Yellow Jasper mix)

Silicon Dioxide (SiO2)

Chrysocolla

Hydrated copper silicates (Cu,Al)2H2Si2O5(OH)4·nH2O

Blue Lace Agate (with Amethyst Geode center)

Silicon Dioxide (SiO2) - Cryptocrystalline Chalcedony

Agate (specifically Waterline or Onyx-type Agate)

Silicon Dioxide (SiO2) - variety Chalcedony

Beryl (likely Aquamarine or Green Beryl)

Beryllium aluminum silicate (Be3Al2Si6O18)

Tourmalinated Quartz

SiO2 with NaFe3+3Al6(BO3)3Si6O18(OH)4 inclusions

Greenschist / Chloritaform Schist

Chlorite Schist (Group of Silicate Minerals)

Fossilized Shark Tooth (Fragment) in Matrix

Elasmobranchii (subclass)

Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

Dinosaur Bone (Fossilized)

Permineralized Bone (CaCO3 or SiO2 after Hydroxylapatite)

Aventurine

Aventurine Quartz (SiO2 with inclusions)

Granite

Granite (silica-rich intrusive igneous rock)

Blue Quartz (Dumortierite Quartz)

SiO2 containing inclusions of Dumortierite [Al7(BO3)(SiO4)3O3]

Greenschist

Greenschist (composed of Chlorite, Actinolite, and Epidote)

Red Sandstone

Arenite (Iron-rich)

Fuchsite

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Greenstone (Epidote/Chlorite-rich Metabasalt)

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

Schist

Mica Schist (primarily Muscovite and Biotite)

Gneiss

Gneiss

Gneiss

Gneiss (a type of metamorphic rock)

Pink Granite

Felsic Plutonic Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)

Turquoise (possible Howlite imitation)

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

Sandstone

Arenite (mainly SiO2 with varying cements)

Sandstone

Arenite

Quartz Geode

Silicon Dioxide (SiO2)

Variscite (or potentially a turquoise/variscite matrix cabochon, or an impression jasper)

AlPO4·2H2O (Variscite) or related phosphate/silicate material depending on exact composition

Howlite and Purpurite druzy

Calcium Borosilicate Hydroxide (Howlite) and Manganese Phosphate (Purpurite)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Tumbled Moonstone

Feldspar (Orthoclase/Albite), KAlSi3O8

Sandstone

Arenite (primarily SiO2)

Turquoise

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

Chalcopyrite

Copper Iron Sulfide (CuFeS2)

Quartz Geode

Silicon Dioxide (SiO2)

Quartz Geode

Quartz (Silicon Dioxide, SiO2) in a Geode

Satin Spar (Satin Spar Selenite)

Gypsum (CaSO4·2H2O)

Satin Spar (often sold as Selenite)

Gypsum (CaSO4·2H2O)

Sandstone

Arenite (SiO2 primarily)

Blue Calcite

Calcium Carbonate (CaCO3)