Man Made Material, Not A Natural Rock Or Mineral Specimen

Granodiorite

Granodiorite (Na,Ca)(Si,Al)4O8

Wishing Stone (Basalt/Greywacke with Quartz Vein)

Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion

Turquoise

Turquoise (Hydrated phosphate of copper and aluminium) CuAl6(PO4)4(OH)8·4H2O

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Pink Quartz (Rose Quartz)

Silicon Dioxide (SiO2)

Sandstone

Clastic Sedimentary Rock (composed primarily of Quartz, SiO2)

Sandstone (with Lichen)

Arenite (primarily SiO2)

Sandstone

Arenite (composed primarily of SiO2)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide cement)

Labradorite

(Ca, Na)(Al, Si)4O8

Milky Quartz

Silicon Dioxide (SiO2)

Geode (Unopened)

Silica-rich Concretion (primarily SiO2)

Granite Gneiss

Gneiss (high-grade metamorphic rock)

Scoria (Volcanic Rock)

Scoria (often basaltic scoria)

Black Tourmaline (Schorl)

Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3(OH)4)

Sandstone

Arenite (Siliclastic sedimentary rock)

Rough Tanzanite

Zoisite (Ca2Al3(SiO4)3(OH))

Boxwork Siderite or Sepatarian Nodule Weathering

Siderite (FeCO3) with secondary mineralization or Boxwork Geode fragment

Quartz with Iron Oxide Monzonite or Sandstone contact

Quartz (SiO2) with Limonite/Hematite staining

Quartz Geode / Druzy Quartz

Silicon Dioxide (SiO2)

Bauxite

Bauxite (Al(OH)3, AlO(OH))

Quartz Druzy on Matrix (likely Agate or Jasper)

Silicon Dioxide (SiO2) with various mineral inclusions

Sandstone

Arenite (primarily SiO2)

Gold Nugget

Native Gold (Au)

Pyrite

Pyrite (FeS2)

Sandstone

Arenite (composed primarily of SiO2)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Quartzite with inclusions

Metamorphic Rock (Mainly SiO2)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 cement)

Quartz vein in metamorphic rock

Crystalline Silicon Dioxide (SiO2) in Host Rock

Pyrite

Iron Disulfide (FeS2)

Iron-stained Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

Sandstone

Arenite (primarily SiO2)

Serpentinite

Serpentinite (composed primarily of minerals in the Serpentine group)

Clear Quartz Cluster

Silicon Dioxide (SiO2)

Agate

Agate (a variety of Chalcedony, SiO2)

Quartz

Quartz (SiO2 - Silicon Dioxide)

Glauconitic Sandstone (Greensand)

Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)

Ferruginous Sandstone (Ironstone)

Arenite with Limonite/Goethite cement

Tiffany Stone

Fluorite Opal (a complex mix of Fluorite, Opal, Calcite, Dolomite, Quartz, and Bertrandite)

Yellow Jasper

Silicon Dioxide (SiO2)

Red Tiger's Eye beads

Tiger's Eye (variety of Chalcedony, SiO2)