Mineral Variant

Sodalite

Sodalite, Na8(Al6Si6O24)Cl2

Pyrite

Iron Sulfide (FeS2)

Satin Spar Selenite

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Basalt with Quartz Vein and Weathering Crust

Amygdaloidal or Porphyritic Basalt

Mica (specimen appears to be Muscovite or Phlogopite)

Phyllosilicate mineral; Muscovite: KAl2(AlSi3O10)(F,OH)2

Amazonite

Microcline (variety Amazonite), K(AlSi3O8)

Olivine (Peridot)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Lapis Lazuli (Tumbled Stone)

Na6Ca2(Al6Si6O24)(SO4,S,Cl)2 (Lazulite-rich Metamorphic Rock)

Sandstone

Arenite (composed primarily of SiO2)

Granite

Phaneritic plutonic rock (primarily Quartz, Feldspar, and Mica)

Schist

Mica Schist

Sandstone (Red)

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

Ironstone Concretion (Limonite/Hematite Nodules)

Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)

Ferruginous Sandstone (Red Sandstone)

Arenite with Hematite/Limonite cement

Ferruginous Quartz (Iron-stained Quartz)

Silicon Dioxide (SiO2) with Hematite/Goethite inclusions

Banded Sandstone (Quartzite-rich)

Clastic Sedimentary Rock (SiO2 with Iron Oxide impurities)

Red Sandstone

Arenite (Ferruginous Sandstone)

Limonite

Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Limonite and Goethite (Ironstone)

Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)

Quartz Pebble

Silicon Dioxide (SiO2)

Ferruginous Quartz (Iron-stained Quartz)

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

Brecciated Chert

Sedimentary Chert (SiO2) with Calc-Silicate mineralization

Jasper (var. Ocean or Polychrome Jasper)

Silicon Dioxide (SiO2) with iron and mineral inclusions

Jasper with Manganese Dendrites

Silicon Dioxide (SiO2) with Oxide Mineral Inclusions

Yellow Ocher (Limonite)

Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O

Rutilated Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2 with Epidote/Tourmaline inclusions

Quartzite Pebble

Quartzite (primarily SiO2)

Schist

Mica Schist

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Blue Quartz (Aventurine)

Silicon Dioxide (SiO2) with fibrous inclusions (commonly Dumortierite)

Quartz Pebble

Silicon Dioxide (SiO2)

Blue Apatite

Apatite (Ca5(PO4)3(F,Cl,OH))

Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Granite

Phaneritic Igneous Rock (Granite)

Geode (unopened)

SiO2 - Chert-shelled concretion (mostly Quartz)

Corundum (Ruby Variety)

Corundum (Al2O3)

Amygdaloidal Basalt with Epidote

Vesicular Basalt with secondary Epidote/Quartz mineral infill

Quartzite River Rock with Dendrites

Metamorphosed Quartz-rich Sandstone with Manganese Oxide (MnO2) inclusions

Honeycomb Calcite

Calcite (Calcium Carbonate, CaCO3)

Black Sapphire

Corundum (Al2O3 with iron and titanium impurities)