Metamorphic And Igneous

Native Gold (in the form of jewelry)

Gold (Au)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Blue Sapphire

Corundum (Al2O3)

Blue Sapphire

Corundum (Al2O3 with trace Titanium/Iron)

Hematite

Iron(III) oxide (Fe2O3)

Quartz in Matrix (or Quartz Vein Rock)

Silicon Dioxide (SiO2) with host rock

Milky Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Milky Quartz with inclusions

Silicon Dioxide (SiO2)

Ruby (Pinkish-Red)

Corundum (Al2O3 with Chromium trace)

Milk Quartz (White) and Yellow Aventurine (Yellow)

Silicon Dioxide (SiO2)

Black Onyx

Silicon Dioxide (SiO2) with parallel banding

Quartz with Pyrite

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)

Auriferous Quartz or Pyritic Ore

Iron Pyrite (FeS2) or Native Gold (Au) in Matrix

Quartz pebble

Silicon dioxide (SiO2)

Rough Gemstone Grains (Mixed Sapphires and Quartz)

Corundum (Al2O3) and Quartz (SiO2)

Quartz / Calcite Vein Rock

Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)

Yellow Sapphire

Corundum (Al2O3)

Black Sapphire (Basaltic Blue Sapphire)

Corundum (Al2O3)

Milky Quartz

Silicon Dioxide (SiO2)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Blue Quartz (or Blue Aventurine)

Silicon Dioxide (SiO2) with inclusions (typically Crocidolite or Dumortierite)

Green Aventurine

Quartz with Fuchsite inclusions (SiO2)

Emerald

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

Quartz Vein on Matrix

Silicon Dioxide (SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Gold Ore in Matrix

Native Gold (Au) in Quartz/Host Rock

Gold Ore

Native Gold (Au) in Matrix

Hematite

Iron(III) oxide (Fe2O3)

Quartz Vein in Host Rock

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

Rose Quartz

Silicon Dioxide with trace inclusions of dumortierite or titanium (SiO2)

Ruby (Pink to Red Corundum)

Al2O3 (Corundum with Chromium impurities)

Milky Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Sandstone (Micaceous Sandstone)

Arenite (SiO2 with KAl2(AlSi3O10)(OH)2 inclusions)

Weathered granite (likely with accessory quartz)

Granite; chiefly quartz, K-feldspar, plagioclase, and biotite/hornblende

Milky Quartz with Matrix

Silicon Dioxide (SiO2)

Milky Quartz (with Iron staining)

Silicon Dioxide (SiO2)

Rough Emerald

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Ruby (Raw Corundum)

Corundum (Al2O3:Cr)

Mica (Biotite or Phlogopite variety)

Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)

Quartz (Pinkish-Orange Variety)

Crystalline Silicon Dioxide (SiO2)

Pyrite on Quartz (Fool's Gold in Quartz)

Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)

Emerald

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