Man Made Alloy (Metallic)

Limonite (also known as Yellow Ochre or Brown Hematite)

Limonite (Hydrated iron oxide-hydroxide, FeO(OH)·nH2O)

Schist

Mica Schist

Peacock Ore

Bornite (Cu5FeS4)

Banded Iron Formation (BIF)

Banded Iron Formation (composed primarily of Hematite [Fe2O3], Magnetite [Fe3O4], and Chert [SiO2])

Basalt with Granite Inclusions (Xenoliths)

Mafic igneous rock (Basalt) with Sialic minerals

Anthracite Coal

Coal (predominantly carbon)

Pyrite

Iron Pyrite (FeS2)

Limonite (after Pyrite Pseudomorph)

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

Pink Fluorite

Fluorite (Calcium Fluoride) - CaF2

Green Fluorite

Calcium Fluoride (CaF2)

Limonite and Goethite (Ironstone)

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

Basalt

Extrusive mafic igneous rock

Silver Sheen Obsidian

Volcanic Glass (Amorphous Silicon Dioxide - SiO2 with impurities)

Indigo Gabbro (also known as Mystic Merlinite)

Gabbro (composed of Plagioclase Feldspar, Pyroxene, and minor Magnetite/Ilmenite)

Obsidian (specifically Silver Sheen Obsidian)

Volcanic Glass (approx. 70–75% SiO2 plus MgO, Fe3O4)

Mica Schist

Mica Schist

Schist

Mica Schist (formula variable based on mineral content, typically containing [K,Al,Fe,Mg,Si,O,H])

Basalt

Basalt (Mafic volcanic rock, primarily Plagioclase and Pyroxene)

Muscovite Schist

Muscovite Mica Schist (KAl2(AlSi3O10)(OH)2)

Fossil / Permineralized Bone

Tyrannosaurus rex fossil (Hydroxylapatite replaced by various minerals)

Basalt

Basalt (extrusive igneous rock)

Gold-bearing Quartz with Iron Oxides

Quartz (SiO2) with Limonite/Goethite (FeO(OH)) and Pyrite (FeS2)

Basalt River Stone (Tumbled)

Basalt (Mafic Extrusive Igneous Rock)

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Mica Schist

Mica Schist (primarily Muscovite and Quartz composition)

Smoky Quartz and Biotite Schist

Quartz-Biotite Schist (SiO2 + K(Mg,Fe)3AlSi3O10(F,OH)2)

Basalt

Basalt (extrusive volcanic mafic rock)

Diabase (also known as Dolerite)

Diabase

Garnet Schist

Almandine-Mica Schist

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Green Aventurine

Silicon Dioxide (Quartz) with inclusions of Fuchsite mica; Chemical formula: SiO2 + K(Al,Cr)2AlSi3O10(OH)2

Scoria

Vesicular Basalt / Scoriaceous Basalt

Jet

Lignite (Anthracite-grade compact coal)

Vesicular Basalt

Mafic Igneous Rock

Mica Schist with Iron Staining

Muscovite/Biotite Schist

Mica Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

Folded Schist / Gneiss (Metamorphic Rock)

Regional Metaphoric Folded Outcrop (predominantly Schist/Gneiss)

Mica Schist

Mica Schist (primarily Muscovite [KAl2(AlSi3O10)(OH)2] or Biotite)

Lepidolite

K(Li,Al)3(Al,Si)4O10(F,OH)2 (Lithium-bearing phyllosilicate)

Basalt

Basalt (Mafic Extrusive)

Botryoidal Hematite (Kidney Ore)

Hematite (Fe2O3)

Lapis Lazuli

Lapis Lazuli (Rock composed primarily of Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, Calcite, and Pyrite)