Metamorphic Or Igneous Alteration

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Quartz with Mafic/Chlorite Veins

Silicon Dioxide (SiO2) with Chlorite/Epidote cross-veining

Milky Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Quartz with Pyrite

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)

Yellow Sapphire

Corundum (Al2O3:Fe)

Diamond and Sapphire

Carbon (Diamond, C) and Aluminum Oxide (Sapphire, Al2O3)

Blue Sapphire

Corundum (Al2O3 with trace Titanium/Iron)

Emerald

Beryl (Be₃Al₂(SiO₃)₆) with Chromium or Vanadium impurities

Quartz pebble

Silicon dioxide (SiO2)

Black Sapphire (Basaltic Blue Sapphire)

Corundum (Al2O3)

Quartz with Epidote

Silicon Dioxide (SiO2) with Calcium Aluminum Iron Silicate [Ca2(Al,Fe)3(SiO4)3(OH)]

Milky quartz

Quartz (silicon dioxide, SiO₂)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) with host rock (often Schist or Basalt)

Prehnite

Prehnite, Ca2Al2Si3O10(OH)2

Dumortierite Quartz

Dumortierite in Quartz (Al6O3(BO3)(SiO4)3)

Green Aventurine

Quartz (SiO2) with fuchsite inclusions

Unakite (likely epidote–feldspar rock)

Epidote–K-feldspar–quartz aggregate; commonly approximated as pink orthoclase/microcline + green epidote + quartz

Epidote in Granite Gneiss

Epidote bearing Orthogneiss (Ca2(Al,Fe)3(SiO4)3(OH))

Milky Quartz with Chlorite/Moss Infusions

Silicon Dioxide (SiO2)

Fuchsite in Quartz

K(Al,Cr)2(AlSi3O10)(OH)2 in SiO2

White Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Quartz (Milky Quartz with Iron Staining)

Silicon Dioxide (SiO2)

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities

Greenstone (Greenschist facies)

Greenschist (composed primarily of Chlorite, Actinolite, and Epidote)

Epidosite (Epidote-rich rock)

Epidosite (consisting primarily of Epidote: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))

Ruby (Pink to Red Corundum)

Al2O3 (Corundum with Chromium impurities)

Parti Sapphire

Corundum (Al2O3)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Epidote

Epidote; Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

Quartz / Calcite Vein Rock

Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)

Pyrite on Quartz

Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)

Epidote

Epidote - Ca2(Al,Fe)3(SiO4)3(OH)

Quartz crystal with Pyrite inclusions

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz (Quartz Vein)

Silicon Dioxide (SiO2)

Red/pink granite or granitic gneiss

Felsic granitoid, chiefly quartz, potassium feldspar, plagioclase, and biotite; exact identification is uncertain from the image

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

Quartzite with Epidote/Chlorite Inclusion

Metamorphic Quartzite (SiO2 with accessory silicate minerals)

Fuchsite (Chrome Mica)

K(Al,Cr)2(AlSi3O10)(OH)2

Magnetite

Magnetite (Fe3O4)

Fuchsite

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Nephrite Jade

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