Not A Geological Specimen

Biotite / Black Mica

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

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Sedimentary or Igneous Matrix

Jasper Breccia

Silicon Dioxide (SiO2) - Brecciated Microcrystalline Quartz

Ferruginous Sandstone (with Iron Oxide staining)

Clastic Sedimentary Rock - Quartz Arenite/Wacke

Chert (Brown Variety)

Microcrystalline quartz (SiO2)

Clear/White Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Quartz (specifically Citrine or Yellow Quartz)

Silicon Dioxide (SiO2)

Clear Quartz Crystal

Quartz (Silicon Dioxide, SiO2)

Granite (Light-colored quartz/feldspar variety)

Granite (composed primarily of Quartz SiO2 and Feldspar KAlSi3O8)

Chromium (Chrome)

Chromium (Cr)

Orange Calcite

Calcium Carbonate (CaCO3)

Amazonite

Potassium Aluminum Silicate (KAlSi3O8)

Quartz (Smoky or Clear variety with inclusions)

Silicon Dioxide (SiO2)

Snowflake Obsidian

Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)

River Pebble (Quartzite/Chert)

Quartzite with inclusions (SiO2)

Pyrite

Iron Sulfide (FeS2)

Porphyritic Basalt (with Augite Crystals)

Porphyritic Mafic Volcanic Rock (Fe-Mg Silicates)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Chatoyant or Milky variety)

Silicon Dioxide (SiO2)

Phantom Quartz with Chlorite and Hematite inclusions

Silicon Dioxide (SiO2) with inclusions of Chlorite group minerals and Hematite (Fe2O3)

Granite with Orthoclase and Hematite Staining

Phaneritic Felsic Igneous Rock (primarily SiO2 with KAlSi3O8)

Chert (and Petrified Wood)

Silicon Dioxide (SiO2)

Hand-Drawn Gengar Pokémon Card Artist Item

Lignocellulosic Fiber (Cellulose, C6H10O5) with wax-based pigment (crayon/colored pencil)

Fossilized Shark Tooth (Dermal Denticle or worn tooth fragment)

Elasmobranchii (fossil remains)

Chert (and Fossilized Brachiopod shell)

Sedimentary Cryptocrystalline Quartz (SiO2)

Granite (Weathered/Oxidized)

Phaneritic Felsic Igneous Rock (composed of Quartz, Orthoclase Feldspar, and Mica)

Quartz Crystal (specifically a milky or semi-translucent single crystal point)

Silicon Dioxide (SiO2)

Sandstone (Quartzose)

Arenite (SiO2 principal)

Crinoid and Coral Fossils in Limestone

Fossiliferous Limestone with Rugosa (order) and Crinoidea (class)

River Rocks (Basalt and Sedimentary Stones)

Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock

Alexandrite in Matrix

Chrysoberyl (BeAl2O4 with Chromium impurities)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide inclusions (Hematite/Goethite)

Boxwork Siderite or Sepatarian Nodule Weathering

Siderite (FeCO3) with secondary mineralization or Boxwork Geode fragment

Clear Quartz

Silicon Dioxide (SiO2)

Yellow Calcite

Calcite (Calcium Carbonate, CaCO3)

Quartz in Matrix (possibly with Biotite or Hornblende)

Quartz (Silicon Dioxide, SiO2) in Granitic Matrix

Quartz

Silicon dioxide (SiO2)

Quartz / Common Agate

Silicon Dioxide (SiO2)

N/A (Non-Geological Object)

Quartz / Rock Crystal

Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)