Amethyst
Amethyst (Silicon Dioxide, SiO2 with Iron impurities)
Category
Browse synthetic or natural fiber specimens identified by the Rock Identifier community.
Amethyst
Amethyst (Silicon Dioxide, SiO2 with Iron impurities)
Smoky Quartz (Vein Quartz)
Quartz (Silicon Dioxide, SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with ferric impurities)
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
Smoky Quartz (Tumbled)
Silicon Dioxide (SiO2)
Amethyst/Smoky Quartz Cluster
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Citrine Quartz
Silicon Dioxide (SiO2)
Limonite Pseudomorph after Pyrite
Goethite/Limonite FeO(OH)·nH2O replacing Pyrite FeS2
Bornite (Peacock Ore)
Bornite (Cu5FeS4)
Concrete Fragment
Hardened Portland Cement Composite
Amber
Succinite (Organic Mineraloid) - C10H16O
Yellow Quartz Pebble
Quartz (Silicon Dioxide - SiO2)
Chrysocolla
Hydrated copper phyllosilicate mineral (Cu,Al)2H2Si2O5(OH)4·n(H2O)
Pearl
Organic gemstone (Calcium carbonate / CaCO3 + Conchiolin)
Crushed Stone / Gravel
Aggregatus saxum (variable mineral composition)
Dyed Agate (Tumbled)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Picture Jasper
Silicon Dioxide (SiO2)
Sandstone
Arenite
Bismuth Crystal
Bismuth (Bi)
Banded Agate (specifically Botswana Agate or Water-line Agate)
Chalcedony (cryptocrystalline variety of Quartz), SiO2
Banded Agate (specifically Gobi Eyes or Eye Agate)
Silicon Dioxide (SiO2) - Variety of Chalcedony
Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
Black Onyx
Silicon Dioxide (SiO2)
Citrine Geode Fragment
Citrine (Silicon Dioxide with Iron Impurities), SiO2
Blue Dyed Agate Geode
Chalcedony (cryptocrystalline Quartz), SiO2
Peacock Ore
Bornite (Cu5FeS4)
Amethyst (Faceted)
Amethyst (Silicon Dioxide with iron impurities, SiO2)
Dyed Quartz Geode
Silicon Dioxide (SiO2) with artificial pigment
Quartz Crystal (specifically a Double-Terminated variety)
Silicon Dioxide (SiO2) - Low Quartz
Smoky Quartz (with Hematite inclusions)
Silicon Dioxide (SiO2)
Agate Slices and Clear Quartz Points
Agate (SiO2 Chalcedony) and Clear Quartz (SiO2 Crystalline)
Dyed Agate Geode (Pink/Magenta)
Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz
Granite
Granite (a phaneritic intrusive igneous rock consisting mainly of quartz, alkali feldspar, and plagioclase)
Granite
Granite (compositional mixture of Quartz, Feldspar, and Mica)
Dyed Howlite (simulating Lavender/Purple Jade or Charoite)
Howlite: Ca2B5SiO9(OH)5 (when natural)
Smoky Quartz
Smoky Quartz (Silicon Dioxide, SiO2)
Green Aura Quartz
Silicon Dioxide (SiO2) bonded with metallic vapors (typically Gold, Chromium, or Titanium)
Strawberry Quartz (Red Aventurine)
Silicon Dioxide (SiO2) with Hematite/Goethite inclusions
Sandstone (Grooved/Weathered)
Arenite (composed primarily of Quartz and Lithic fragments)
Amethyst
Silicon Dioxide with trace inclusions of Iron (SiO2)
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]