Quartzite
Quartzite (Primary mineral: Silicon Dioxide, SiO₂)
Category
Browse non geological specimens identified by the Rock Identifier community.
Quartzite
Quartzite (Primary mineral: Silicon Dioxide, SiO₂)
Mahogany Obsidian
Obsidian (SiO2 + Fe2O3)
Quartzite
Quartzite (primarily SiO2)
Black Obsidian
Amorphous volcanic glass (SiO2 + impurities)
Quartzite
Quartzite (primarily SiO2)
Obsidian
Obsidian (volcanic glass), amorphous SiO2 + impurities
Obsidian
Obsidian (Extrusive Volcanic Glass)
Quartzite
Quartzite (SiO2)
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Volcanic glass (mainly SiO2)
Milky quartz (rough quartz specimen)
Quartz, silicon dioxide (SiO₂)
Obsidian
Obsidian (volcanic glass; primarily SiO2)
Quartzite
Metamorphic Quartzite (SiO2)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Obsidian
Volcanic Glass (SiO2)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Black Obsidian
Obsidian (Volcanic Glass)
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
Limonite
Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)
Black Obsidian
Volcanic Glass (SiO2)
Obsidian
Obsidian (Volcanic Glass)
Black Obsidian
Volcanic Glass (SiO2 + impurities)
Snowflake Obsidian
Obsidian with Cristobalite inclusions (70–75% SiO2)
Quartzite
Metamorphic Quartzite (SiO2)
Dalmatian jasper
Orbicular microcrystalline quartz rock, commonly rhyolitic or volcanic-feldspar matrix with black arfvedsonite/alkali-amphibole inclusions
Quartzite
Quartzite (primarily SiO2)
Grey Quartzite Pebble
Quartzite (primarily SiO2 - Silicon Dioxide)
Siltstone
Siltstone
Black Obsidian
Obsidian (Volcanic Glass)
Slag Glass (Cullet Glass)
Amorphous Silica (Industrial byproduct)
Obsidian
Obsidian (Volcanic Glass)
Quartzite
Metamorphic Quartzite (primarily SiO2)
Blue Sapphire (Ceylon)
Corundum (Al2O3) with traces of Iron and Titanium
Sandstone
Sedimentary Clastic Rock (Quartz Arenite)
Common Opal (Green Opal / Pistachio Opal)
Hydrated silica (SiO2·nH2O)
Obsidian
Obsidian (Amorphous volcanic glass)
Obsidian
Obsidian (Volcanic Glass)
Obsidian (worked into an arrowhead profile)
Obsidian (volcanic glass), primarily SiO2 (Silicon Dioxide)
Red cabochon gemstone, likely carnelian or dyed chalcedony
Chalcedony (microcrystalline quartz), SiO₂; exact identification requires testing
Quartzite
Metamorphic Quartzite (SiO2)
Obsidian (specifically Mahogany Obsidian)
Volcanic glass (high silica content, SiO2)
Obsidian
Obsidian (Volcanic Glass)