Mineral (Biogenic)

Herkimer Diamond (Quartz Crystal)

Silicon Dioxide (SiO2)

Amethyst (as seen in jewelry)

Silicon Dioxide (SiO2) with iron impurities

Amethyst Quartz

Amethyst (Silicon Dioxide, SiO2)

Amethyst (Polished Cabochon)

Silicon Dioxide (SiO2) with iron impurities

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Amazonite

K(AlSi3O8), Microcline

Amethyst (Pale/Light Variety)

Quartz (Silicon Dioxide) with Iron impurities - SiO2

Snowflake Obsidian

Spherulitic Obsidian (Amorphous Volcanic Glass with Cristobalite inclusions)

Granite Cobble

Granite (Phaneritic igneous rock)

Granite

Felsic Plutonic Rock

Ocean Jasper (Orbicular Jasper)

Silicon Dioxide (SiO2) with various inclusions

Gneiss (with Quartzite and Biotite)

Gneiss containing SiO2 (Quartz), K(Mg,Fe)3AlSi3O10(OH)2 (Biotite), and (K,Na,Ca)AlSi3O8 (Feldspar)

Basalt with Quartz Vein

Mafic Igneous Rock (SiO2 filling)

Orange Calcite

Calcite (CaCO3)

Quartz (White/Milky Pebble)

Silicon Dioxide (SiO2)

Aventurine

Aventurine Quartz (SiO2 with Fuchsite inclusions)

Silicon Carbide (Carborundum)

Moissanite (SiC)

Granite

Phaneritic Plutonic Rock (primarily SiO2, Al2O3, K2O, Na2O)

Gneiss (Schistose)

Gneiss

Green Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite mica

Garnet

Garnet Group (Silicate Minerals), formula varies e.g., Almandine Fe3Al2(SiO4)3

Conglomerate

Conglomerate (clastic sedimentary rock)

Quartzwacke / Impure Sandstone

Arenite with minor lithic fragments (Silicon Dioxide matrix)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Greenschist (Greenstone)

Greenschist (Metamorphic rock containing chlorite, actinolite, and epidote)

Granite

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

Pyrite

Iron Sulfide (FeS2)

Gypsum (Alabaster variety)

Calcium sulfate dihydrate (CaSO4·2H2O)

Sodalite

Sodalite, Na8(Al6Si6O24)Cl2

Satin Spar Selenite

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Pyrite

Iron Sulfide (FeS2)

Amygdaloidal Basalt

Basalt with secondary mineral infilling (commonly Zeolite, Calcite, or Quartz)

Barite

Barium Sulfate (BaSO4)

Martian Meteorite (Black Beauty)

NWA 7034 (Northwest Africa 7034)

Basalt with Sulfide/Pyrite inclusion

Aphanitic Mafic Igneous Rock (likely Basalt) with Pyrite (FeS2)

Quartzite River Rock

Quartzite (primarily SiO2)

Sandstone (Ferruginous)

Arenite with Iron Oxide cement

Fossilized Fish (Lepidotes)

Lepidotes sp. (Order: Lepisosteiformes)

Glauconite (Glauconitic Sandstone)

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

Chrysocolla (with Quartz and Azurite)

Hydrated copper phyllosilicate mineral [Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)]

Coprolite

Coprolite

Lava Stone and Chakra Beads

Basalt (with various mineral/synthetic beads)