Igneous (Anthropogenic)

Ruby (Corundum)

Corundum (Aluminum Oxide) with chromium trace elements, Al2O3

Moonstone

Orthoclase Feldspar (containing Albite lamellae), (KAlSi3O8)

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Carnelian Agate

Silicon Dioxide (SiO2) - variety of Chalcedony

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

Carnelian Agate

Silicon Dioxide (SiO2) - Chalcedony containing Iron Oxide impurities

White Quartz

Silicon Dioxide (SiO2)

Blue Sapphire

Corundum (Al2O3)

Blue Lace Agate

Silicon Dioxide (SiO2) - Variety of Chalcedony

Amazonite

K(AlSi3O8), Microcline

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Labradorite

Feldspar (Plagioclase Series), (Ca,Na)(Al,Si)4O8

Rose Quartz

Silicon Dioxide (SiO2)

Peridot

Olivine (Magnesium Iron Silicate), (Mg, Fe)2SiO4

Sand (Construction Grade)

Unconsolidated siliciclastic sediment (primarily SiO2)

Olivine (Peridot)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Quartz (specifically Citrine or Iron-stained Quartz)

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Black Spinel

Magnesium Aluminum Oxide (MgAl2O4)

Bornite

Bornite (Cu5FeS4)

Amazonite

Potassium Feldspar (KAlSi3O8)

Smoky Quartz

Silicon Dioxide (SiO2)

Quartz (possibly Citrine or Smoky Quartz variety)

Silicon Dioxide (SiO2)

Kaolinite (Chalky Clay)

Kaolinite (Al2Si2O5(OH)4)

Rose Quartz

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

Hematite

Iron(III) oxide (Fe2O3)

Granite (weathered)

Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)

Granite Cobble

Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)

Granite

Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)

Granite (River-worn Cobble)

Phaneritic Felsic Igneous Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)

Granite

Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)

Granite

Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)

Granite

Phaneritic Felsic Igneous Rock (Main minerals: SiO2, KAlSi3O8, NaAlSi3O8)

Pink Granite (Alkali Feldspar Granite)

Phaneritic Felsic Igneous Rock (composed primarily of KAlSi3O8, SiO2, and NaAlSi3O8)

Pumice

Pumice (a highly vesicular extrusive igneous rock, primarily amorphous silica)

Basalt

Extrusive Mafic Igneous Rock (composed primarily of Plagioclase, Pyroxene, and Olivine)

Granite

Granite (Phaneritic Igneous Rock; primarily Quartz, Alkali Feldspar, and Plagioclase)

Granite with Quartz Vein

Phaneritic Felsic Igneous Rock (composed of Quartz [SiO2], Feldspar, and Mica)

Diorite

Phaneritic Intrusive Igneous Rock (composed of Plagioclase feldspar, Hornblende, and Biotite)

Granite

Phaneritic Felsic Igneous Rock (primarily SiO2, Al2O3, K2O, Na2O)

Pink Granite

Phaneritic Plutonic Igneous Rock (composed of K-feldspar, Quartz, and Mica)