This Is Not A Rock Or Mineral

Unakite

Unakitized granodiorite / Quartz-Epidote-Feldspar rock

Dyed Agate (Tumbled)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chrome Diopside

Magnesium Calcium Silicate (MgCaSi2O6) containing Chromium impurities

Moss Agate

Silicon Dioxide with inclusions (SiO2 + impurities)

Chert (or Flint)

Chert (Sedimentary Cryptocrystalline Sio2)

Fossiliferous Chert (with Brachiopod or Mollusk fragments)

Silicon dioxide (SiO2) with Calcium Carbonate (CaCO3) inclusions

Basalt

Basalt (Aphanitic Mafic Volcanic Rock)

Jasper (Iron-stained Chalcedony)

SiO2 with Fe2O3 (Iron Oxide) impurities

Agate (specifically, a slice of a Blue Lace or Chalcedony Agate nodule)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Banded Agate / Lace Agate

Agate (Silica/Quartz) - SiO2

Citrine Geode Fragment

Citrine (Silicon Dioxide with Iron Impurities), SiO2

Pink Granite (Potassium-rich Granite)

Phaneritic Felsic Igneous Rock (primarily SiO2, Al2O3, K2O)

Mica Schist

Mica Schist (Complex Silicate Rock)

Diorite

Diorite (intermediate intrusive igneous rock)

Granite (Weathered)

Course-grained Intrusive Igneous Rock

Jasper with Quartz inclusions

Silicon Dioxide (SiO2) with varying mineral impurities

Lapis Lazuli (Lazurite crystals on Marble)

Lazurite / (Na,Ca)8[(S,Cl,SO4,OH)2|(AlSiO4)6]

Quartzite River Pebble

Quartzite (primarily Silicon Dioxide, SiO2)

Ferruginous Sandstone (Ironstone)

Sandstone with Hematite/Goethite cement (SiO2 + FeO(OH))

Obsidian (Arrowhead Lithic Tool)

Obsidian (Amorphous Volcanic Glass / SiO2 + inclusions)

Quartzite

Quartzite (primarily SiO2)

Ferruginous Chert

Microcrystalline Quartz (SiO2) with Iron Oxides

Obsidian

Obsidian (Volcanic Glass; SiO2 content > 70%)

Amethyst

Amethyst (Silicon Dioxide, SiO2 with Iron impurities)

Black Onyx

Silicon dioxide (SiO2) - Chalcedony variety

Green Aventurine in Host Rock

SiO2 (Quartz with Fuchsite inclusions)

Septarian Nodule (Dragon Stone)

Septarian concretion (Complex of Calcite, Aragonite, and Limestone/Clay)

Ironstone Concretion / Limonite-stained Siltstone

Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite/Goethite inclusions

Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

Red Quartzite (River Pebble)

Quartzite (primarily Silicon Dioxide - SiO2)

Chert Pebble with Quartz Veins

Microcrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood)

Silicified Wood / Silicon Dioxide (SiO2)

Gneiss

Gneiss (High-grade regional metamorphic rock)

Quartzite Pebble

Quartzite (SiO2)

Diamond

Diamond (pure Carbon, C)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Agate (specifically a Thunderegg/Agate Nodule)

Cryptocrystalline Quartz (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Sandstone (Ferruginous)

Arenite (Fe-rich)

Siltstone/Sandstone (possibly Wonderstone or Picture Sandstone)

Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide inclusions)