Metamorphic

Ferruginous Quartz (Iron-stained Quartz)

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

Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Epidote with Magnetite/Hematite inclusions

Epidote (Ca2(Al2,Fe3+)(SiO4)3(OH)) with Iron Oxides

Quartz (Milky Quartz with Iron Staining)

Silicon Dioxide (SiO2)

Ruby in Zoisite

Ruby (Corundum, Al2O3) in Zoisite (Calcium aluminum silicate hydroxide, Ca2Al3(SiO4)3(OH)) with some Hornblende

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Gneiss

Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Mica/Amphibole)

Banded Gneiss

Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Biotite/Amphiboles)

Quartzite

Quartzite (primarily SiO2)

Garnet

Garnet Group (complex nesosilicates with general formula X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+, V3+)

Schist

Schist (various compositions)

Quartzite

Quartzite (primarily SiO2)

Banded Gneiss (with possible weathered sulfide or iron staining)

Gneiss, potentially with iron oxide/hydroxide staining (e.g., limonite) or weathered sulfides

Granite (with Almandine Garnet inclusions)

Granite composed primarily of Quartz (SiO2), K-Feldspar (KAlSi3O8), and Almandine Garnet (Fe3Al2(SiO4)3)

Green Quartzite

Metamorphic rock primarily composed of Silicon Dioxide (SiO2) with mineral inclusions like fuchsite or chlorite

Banded Rock (likely Quartz-rich)

Uncertain, likely a Metamorphic Rock (e.g., Gneiss or Schist) with prominent Quartz and other minerals

Banded Slate or Siltstone with Quartz/Calcite Veins

Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Sedimentary/Metamorphic Matrix

Gneiss (with Quartz-Feldspar vein)

Gneiss (high-grade metamorphic rock) containing Quartz (SiO2) and Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8)

Biotite (Mica)

Biotite group (K(Mg,Fe)3AlSi3O10(F,OH)2)

Emerald

Beryl (Be₃Al₂Si₆O₁₈), specifically the green variety colored by trace amounts of chromium or vanadium.

Sapphire (Corundum variety)

Sapphire (Al₂O₃)

Chalcopyrite

Chalcopyrite (CuFeS2)

Tiger's Eye

Tiger's Eye (a variety of Chalcedony, which is a microcrystalline quartz with fibrous inclusions of oxidized crocidolite)

Jade (Nephrite or Jadeite)

Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (Na(Al,Fe3+)Si2O6)

Pink Quartzite

Quartzite (SiO2)

Garnet (Red Garnet)

Garnet Group. The red varieties seen in jewelry are typically Almandine (Fe3Al2(SiO4)3), Pyrope (Mg3Al2(SiO4)3), or a mix of the two (pyrope-almandine series).

Muscovite Mica

Muscovite - KAl2(AlSi3O10)(OH)2

Biotite (Black Mica)

Biotite [K(Mg,Fe)3(AlSi3O10)(F,OH)2]

Orthoclase Feldspar

Potassium Aluminum Silicate (KAlSi3O8)

Hematite

Iron(III) oxide (Fe2O3)

Muscovite Mica (with Quartz matrix)

Muscovite - KAl2(AlSi3O10)(OH)2

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Green Quartz (Prasiolite/Adventurine)

Silicon Dioxide (SiO2) with inclusions

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Pearl and Garnet Glass

Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass

Amethyst

Silicon Dioxide (SiO2) containing iron impurities

Citrine Quartz

Silicon Dioxide (SiO2) with ferric iron impurities

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Muscovite Mica (on Quartz Matrix)

Muscovite - KAl2(AlSi3O10)(OH)2

Sugilite

KNa2(Fe,Mn,Al)2Li3Si12O30 (Potassium Sodium Lithium Iron Manganese Aluminum Silicate)