Silicon
Crystalline Silicon (Si)
Category
Browse mineraloid (synthetic) specimens identified by the Rock Identifier community.
Silicon
Crystalline Silicon (Si)
Cubic Zirconia (Simulated Diamond)
Zirconium dioxide (ZrO2)
Pearl (Biogenic Mineraloid)
Calcium carbonate (Aragonite) and Conchiolin, CaCO3
K2 Stone (or K2 Jasper)
Azurite-in-Granite (Potassium Feldspar, Quartz, Plagioclase, Muscovite, and Azurite)
Dyed Agate Geode
Silicon Dioxide (SiO2) with artificial pigment
Asphalt (Bituminous Concrete)
Bituminous mix / Anthropogenic conglomerate
Clear Quartz (Faceted) / White Sapphire / Goshenite
Silicon Dioxide (SiO2) / Aluminium Oxide (Al2O3)
Amethyst (Tumbled)
Silicon Dioxide (SiO2) with Fe3+ impurities
Blue faceted gemstones, likely blue sapphire
Corundum (Al₂O₃), blue varieties colored chiefly by iron and titanium
Polished mahogany obsidian (likely)
Volcanic glass; primarily silica-rich rhyolitic glass (SiO₂), with iron oxides
Polished black obsidian pyramid/block
Obsidian — natural volcanic glass, chiefly rhyolitic silica (approximately 70–75% SiO₂)
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite/Magnetite inclusions)
Mahogany Obsidian
Obsidian (Volcanic Glass with Hematite inclusions)
Gold Sheen Obsidian
Volcanic Glass (SiO2 + impurities)
Snowflake Obsidian
Volcanic Glass with Spherulite Inclusions (primarily SiO2)
Black Obsidian
Obsidian (Volcanic Glass)
Snowflake Obsidian
Volcanic Glass with Spherulite Inclusions (70–75% SiO2)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Limonitic Iron Ore / Goethite
Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)
Obsidian
Obsidian (Volcanic Glass, SiO2)
Limonite (Iron Ore)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with inclusions of Hematite or Magnetite)
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (mostly SiO2)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
Opalite
Synthetic Glass (Hydrated Silica Simulant)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions
Black Obsidian
Obsidian (Volcanic Glass, ~70% SiO2)
Obsidian
Volcanic Glass (SiO2)
Snowflake Obsidian (Flower Jasper variant)
Vitreous volcanic silicate with cristobalite inclusions
Mahogany Obsidian
Volcanic Glass (Silicate: SiO2 + Fe2O3)
Obsidian
Volcanic Glass (SiO2 rich)
Limonite (with Pyrite)
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
Limonite (Ironstone Concretion)
Limonite (Hydrated iron(III) oxide-hydroxide, mixtures of FeO(OH)·nH2O)
Sedimentary Rock with Crafts (Pet Rock)
Sedimentary rock decorated with synthetic materials
Opalite
Synthetic Glass (Simulated Moonstone/Opal)
Opalite
Synthetic Opalite (Man-made glass)
Pink Dyed Agate
Silicon Dioxide (SiO2) with synthetic pigment
Dyed Quartzite
Metamorphosed Quartz (SiO2) with synthetic pigment
Dyed Crackle Quartz
Silicon Dioxide (SiO2) with synthetic dye
Goldstone
N/A (Synthetic Glass with Copper Inclusions)
Opalite (Synthetic Opalized Glass)
Synthetic Silicon Dioxide (SiO2) glass