Anthropogenic Specimen (Man Made)

Schist with Schorl (Black Tourmaline)

NaFe3Al6(BO3)3Si6O18(OH)4 (Schorl)

Quartz (Smoky/Milky variety with matrix)

Silicon Dioxide (SiO2)

Banded Quartzite River Pebble

Metamorphosed Quartz-rich Sandstone (SiO2)

Chert (Yellow Jasper)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Agatized Fossil or Chalcedony Nodule

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Sandstone (Ferruginous/Red Sandstone)

Clastic sedimentary rock (primarily SiO2 with Fe2O3)

River Pebble (Quartz/Jasper)

Silicon Dioxide (SiO2)

Granite Cobble

Phaneritic Felsic Igneous Rock

Banded Agate

Cryptocrystalline Quartz (SiO2)

Ferruginous Quartz Cobble

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Quartz Geode

Silicon Dioxide (SiO2)

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with fossil inclusions

Obsidian / Chert (Arrowhead Artifact)

Obsidian (volcanic glass, SiO2 with impurities)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Iron Meteorite (Campo del Cielo)

Iron Meteorite, Group IAB (FeNi Alloy: Kamacite and Taenite)

Sandstone (with Liesegang rings or Oxidation)

Arenite (primarily Quartz SiO2 with Iron Oxide Fe2O3 staining)

Limonite-stained Quartz

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

Vesicular Basalt (Aqueous Tumbled)

Scoriaceous Basalt

Agate (Geode nodule fragment)

Chalcedony (cryptocrystalline variety of Quartz), SiO2

Fossiliferous Limestone (Coquina / Shell Limestone)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Sandstone (Beach Pebble)

Clastic sedimentary rock (primarily Quartz and Feldspar)

Limestone (specifically Chalky Limestone)

Calcium Carbonate (CaCO3 / Calcite)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartzite Pebble

Metamorphosed Sandstone (SiO2)

Crushed Limestone Aggregate

Limestone (Calcium Carbonate, CaCO3)

Granite Pebble

Phaneritic Felsic Igneous Rock

Quartz Pebble

Silicon Dioxide (SiO2)

Quartzite

Quartzite (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Mica Schist

Mica Schist

Milky Quartz

Silicon Dioxide (SiO2)

Jasper (Imperial Jasper style)

Silicon Dioxide (SiO2) with impurities

Snowflake Obsidian

Volcanic glass with Spherulite inclusions (SiO2)

Herkimer Diamond

Quartz (Silicon Dioxide, SiO2)

Jasper (Petrified Wood Variety)

Silicon Dioxide (SiO2)

Blue Lace Agate (with Amethyst Geode center)

Silicon Dioxide (SiO2) - Cryptocrystalline Chalcedony

Limestone

Calcium Carbonate (CaCO3)

Basalt with Vesicular Texture (Beach Cobble)

Vesicular Basalt (Aphanitic Igneous Rock)

Sandstone (Micaceous)

Arenite (composed primarily of SiO2)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Quartz (Double-Terminated)

Silicon Dioxide (SiO2)

Chevron Amethyst

Silicon Dioxide (SiO2) with iron impurities