Mineral, Part Of A Rock

Iron-stained Quartz

Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3/FeO(OH))

Sandstone

Arenite (SiO2 based)

Red Sandstone

Arenite (primarily Quartz, SiO2, with Iron Oxide cementing agent)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Brown Sandstone

Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)

Sandstone

Arenite

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Sandstone

Arenite (primarily SiO2)

Granite (with alteration)

Granite (Felsic intrusive igneous rock)

Sandstone

Arenite

Quartz Druzy on Geode Fragment

Silicon Dioxide (SiO2)

Note: Item is not a geological specimen

Guitar Components (Steel, Nickel, Plastic, Wood)

Lapis Lazuli (Raw Ore)

Na8[Al6Si6O24]n(S,Cl,SO4,OH)2 (Lazurite component)

Quartz

Silicon Dioxide (SiO2)

Diorite

Diorite (Intermediate intrusive igneous rock)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Metasedimentary or Igneous matrix

Amygdaloidal Basalt

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

Sandstone

Arenite (primarily SiO2)

Sandstone (likely Arkosic or Lithic Sandstone)

Arenite (SiO2 based with mineral inclusions)

Ferruginous Sandstone (Ironstone)

Clastic Sedimentary Rock (composed of SiO2 with Fe2O3/FeO(OH) cement)

Sandstone (Pebble/Conglomerate fragment)

Sandstone (clastic sedimentary rock)

Sandstone (Ferruginous)

Arenite (Fe-rich)

Schist with Quartz Vein

Mica Schist with Crystalline Quartz (SiO2)

Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Pyrite (on host rock)

Iron Sulfide (FeS2)

Greenstone / Diorite

Intermediate plutonic igneous rock

Carnelian Agate

Silicon Dioxide (SiO2) with iron oxide impurities

Sandstone with Calcite Vein

Clastic sedimentary rock (primarily SiO2) with Calcium Carbonate (CaCO3) infilling

Druzy Quartz on Agate/Chert

Silicon Dioxide (SiO2)

Mica Schist

Mica Schist

Mica Schist

Schist (Crystalline metamorphic rock)

Granitic Gneiss

Gneiss (Metamorphic rock of granitic composition)

Quartz pebble

Silicon dioxide (SiO2)

Barite Rose (Desert Rose)

Barium Sulfate (BaSO4)

Shale

Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)

Goldstone

Not a natural mineral or rock. It is an ornamental glass.

Lapis Lazuli

Na8(Al6Si6O24)S2 (Lazurite is the primary constituent mineral)

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Quartz (Milky or Smoky variety)

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Limonite (after Pyrite Pseudomorph)

Limonite (Hydrated Iron Oxide Mixture, FeO(OH)·nH2O)