Black Obsidian
Obsidian, volcanic glass (Amorphous SiO₂)
Category
Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.
Black Obsidian
Obsidian, volcanic glass (Amorphous SiO₂)
Quartz (Iron-Stained Quartz Pebble)
Silicon Dioxide (SiO2)
Chert (with Manganese Dendrites)
Chert (Cryptocrystalline Quartz, SiO2)
Concrete / Conglomerate (Man-made)
Artificial Conglomerate (Cementitious Composite)
Arfvedsonite (often mistakenly sold as Astrophyllite)
Arfvedsonite [Na3(Fe2+)4Fe3+Si8O22(OH)2]
Opalite
Man-made synthetic glass with opalescent effects (SiO2 + metal oxides)
White Quartzite
Quartzite (primarily SiO2 - Silicon Dioxide)
Chalcopyrite
Chalcopyrite (CuFeS2)
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Obsidian (volcanic glass), predominantly amorphous SiO₂
Sodalite-rich Syenite (Sunset Sodalite)
Sodalite-Syenite (Na8[Al6Si6O24]Cl2 with KAlSi3O8)
Obsidian
Obsidian (volcanic glass; primarily SiO2)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Obsidian
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
Obsidian
Obsidian (Volcanic Glass)
Quartzite
Quartzite (SiO2)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions
Obsidian
Volcanic Glass (predominantly SiO2)
Quartz (Milky/River Quartz)
Silicon Dioxide (SiO2)
Quartzite Pebble
Quartzite (SiO2 with minor impurities)
Pyrite (on Quartz matrix)
Iron Disulfide (FeS2)
Sandstone (with Iron Siderite Concretion)
Arenite with Ironstone Concretion (FeCO3)
Manganese Oxide Crust on Limestone
Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3
Obsidian
Volcanic Glass (predominantly SiO2)
Mica Schist with Pyrite
Muscovite/Biotite Schist with Iron Sulfide (FeS2)
Mica-rich Sandstone or Micaceous Schist Weathering
Micaceous Schist (Muscovite-Quartz composition)
Silver (Native Element)
Ag (Argentum)
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (70–75% SiO2)
Quartzite
Quartzite (primarily SiO2)
Obsidian
Obsidian (principally SiO2 with MgO and Fe3O4)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide)
Obsidian
Obsidian (Volcanic Glass)
Green Glass Cullet / Recycled Glass
Amorphous Silicon Dioxide (SiO2) with various metal oxides
Quartzite
Quartzite (primarily SiO2)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite (SiO2 + Fe2O3)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Aura Quartz (Pink/Rose Aura Quartz)
Silicon Dioxide (SiO2) bonded with Platinum and/or Silver
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
Obsidian
Obsidian (volcanic glass)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Obsidian
Volcanic Glass (SiO2 + impurities)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)