Mineral (Organic Gemstone)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Carnelian (Chalcedony)

Silicon Dioxide (SiO2)

K2 Jasper (K2 Granite)

Azurite in Granite (Al2Cu3(CO3)2(OH)2 in NaAlSi3O8)

Moonstone (Feldspar variety)

Orthoclase Feldspar (KAlSi3O8)

Yellow Topaz (Imperial or Precious Topaz)

Al2SiO4(F,OH)2 (Aluminum Silicate Fluoride Hydroxide)

Emerald

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

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Blue Chalcedony

Chalcedony (a cryptocrystalline variety of Quartz - SiO₂)

Milky Quartz

Silicon Dioxide (SiO2)

Yellow Quartz (Citrine/Lemon Quartz)

Silicon Dioxide (SiO2)

Amethyst

Silicon Dioxide (SiO2) containing Iron impurities

Amethyst (Rose-tinted/Pale variety)

Silicon Dioxide (SiO2) with iron impurities

Aquamarine

Beryl (Be3Al2Si6O18 with iron impurities)

Morganite (Pink Beryl)

Beryllium aluminum silicate Be3Al2(SiO3)6

Amazonite with Smoky Quartz and Feldspar

Microcline (KAlSi3O8) with Quartz (SiO2)

Tiger's Eye

Silicon Dioxide (SiO2) with Limonite/Goethite pseudomorphs after Crocidolite

Chlorastrolite (Greenstone)

Chlorastrolite (variety of Pumpellyite) - Ca2(Mg,Fe)Al2(SiO4)(Si2O7)(OH)2 · H2O

Blue Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of asbestiform silicates)

Sunstone

Aventurine Feldspar (Plagioclase Feldspar with inclusions)

Red Beryl

Bixbite (Be3Al2Si6O18 with Mn3+ ions)

Citrine

Citrine (Silicon Dioxide, SiO2)

Amethyst

SiO2 (Silicon Dioxide with iron impurities)

Amethyst with Marcasite accents

Amethyst (Silicon Dioxide SiO2) and Marcasite (Iron Sulfide FeS2)

Citrine

Silicon Dioxide (SiO2) - Yellow Quartz variety

Yellow Quartz (Citrine Quartz Pebble)

Silicon Dioxide (SiO2)

Peridot (Olivine)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Amazonite

Amazonite (KAlSi3O8); a green variety of Microcline feldspar

Amethyst

SiO2 (Silicon Dioxide) with Iron (Fe3+) impurities

Rough Citrine Quartz

Citrine (Silicon Dioxide, SiO2 with iron impurities)

Smoky Quartz

Smoky Quartz (Silicon Dioxide - SiO2)

Black Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Lapis Lazuli

Sodium aluminum silicate with sulfur (main component: Lazurite [(Na,Ca)8(AlSiO4)6(SO4,S,Cl)2])

Quartz Geode

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Pearl (Imitation or Cultured)

Calcium Carbonate (Aragonite/Calcite) - CaCO3

Raw Corundum (Sapphire/Ruby variant)

Aluminum oxide (Al2O3)

Petrified Wood

Silicified wood (primarily Silicon Dioxide - SiO2)

Chert (Flint Nodules)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (varieties include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Hypersthene

(Mg,Fe)SiO3 - Enstatite-Ferrosilite series

Diamond (or Cubic Zirconia)

Carbon (C) or Zirconium Dioxide (ZrO2)

Yellow Chert (Jasper)

Microcrystalline Quartz (SiO2)