Metamorphic Rock (Primarily Composed Of Minerals)

Foliated Gneiss (River-Worn Pebble)

Gneiss (High-grade Regional Metamorphic Rock)

Peacock Ore (Bornite or Chalcopyrite treated with acid)

Bornite (Cu5FeS4) or Acid-washed Chalcopyrite (CuFeS2)

Hematite Nodules (Moqui Marbles style)

Iron Oxide (Fe2O3)

Milky Quartz

Silicon Dioxide (SiO2)

Shale

Fissile mudstone (primarily clay minerals and silt-sized quartz)

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Anthracite Coal

Anthracite (Carbon-based sedimentary-derived metamorphic rock)

Sandstone (Red)

Arenite (primarily Quartz, SiO2, with Iron Oxide cement)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Petrified Wood

Silicified Wood (primarily SiO₂ / Silicon Dioxide)

Schist

Mica Schist (Composition typically involves Muscovite, Biotite, Quartz, and Feldspar)

Milky Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Amygdaloidal Rhyolite

Rhyolite (felsic volcanic rock) with amygdules

Dyed Agate

Silicon Dioxide (SiO2) - variety Chalcedony

Pink Quartzite

Quartzite (primarily SiO2 with trace Fe2O3)

Quartz with Chalcopyrite and Pyrite

Silicon Dioxide (SiO2) with Copper Iron Sulfide (CuFeS2)

Aventurine (likely Green Aventurine)

Aventurine (a variety of quartz, SiO₂, with common inclusions of fuchsite)

Desert Rose (Baryte/Gypsum Rosette)

Baryte (BaSO4) or Gypsum (CaSO4·2H2O)

Milky Quartz (Common Quartz)

Quartz (Silicon Dioxide, SiO2)

Granite

Granite (a common term for a felsic intrusive igneous rock)

Milky Quartz

Silicon Dioxide (SiO2)

Sapphire (Corundum variety)

Sapphire (Al₂O₃)

Geode (Unopened)

Silica-lined Vug (primarily SiO2)

Anthracite Coal

Anthracite (Carbon-based metamorphic rock, 86-97% C)

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Amygdaloidal Basalt

Amygdaloidal Basalt (containing secondary minerals like Quartz, Zeolites, or Calcite)

Schist

Mica Schist

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

White Marble

Recrystallized Calcite (CaCO3)

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Wishing Stone (Quartz-veined Siltstone or Graywacke)

Hydrothermal Quartz vein in matrix of SiO2 (Quartz) and Al2O3 (Clay minerals)

Orthoclase Feldspar

Potassium Feldspar (KAlSi3O8)

Milky Quartz (Gold-bearing Prospecting Specimen)

Silicon Dioxide (SiO2)

Quartz (Milky Quartz / Quartzite)

Silicon Dioxide (SiO2)

Quartzite

Quartzite (Primary mineral: Silicon Dioxide, SiO₂)

Magnetite / Iron Ore

Magnetite (Fe3O4)

Tiger's Eye

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

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Orthoclase Feldspar

KAlSi3O8 (Potassium Aluminum Silicate)

Basalt

Mafic Volcanic Rock (composed mainly of Plagioclase, Pyroxene, and Olivine)