Obsidian
Obsidian (Volcanic Glass, ~70% SiO2)
Category
Browse mineraloid (man made glass) specimens identified by the Rock Identifier community.
Obsidian
Obsidian (Volcanic Glass, ~70% SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Granite Pebble
Felsic Intrusive Igneous Rock
Aquamarine with Ruby Accent
Beryllium Aluminum Silicate (Be3Al2Si6O18) with Aluminum Oxide (Al2O3)
White Topaz
Al2SiO4(F,OH)2
Tektite (Indochinite)
Tektite (Natural silica glass)
Quartz (Pale Rose or Milky Variety)
Silicon Dioxide (SiO2)
Quartzite Pebble
Metamorphic rock predominantly composed of Quartz (SiO2)
Pumice
Pumice (volcanic glass rock)
Red Granite
Phaneritic Felsic Intrusive Igneous Rock (primarily K-feldspar, Quartz, and Biotite)
Green glass-like cabochon, likely synthetic glass or resin
Unidentified green transparent material; possibly molded glass, synthetic spinel, or resin
Milky quartz
Quartz (silicon dioxide, SiO₂)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Limestone
Calcium Carbonate (CaCO3)
Milky Quartz
Silicon Dioxide (SiO2)
Chert (Gravel)
Silicon Dioxide (SiO2)
Clear quartz crystal point
Quartz (silicon dioxide, SiO₂), likely a polished or cut crystal
Smoky quartz fragment
Quartz, silicon dioxide (SiO₂), smoky variety
Tumbled chalcedony (likely blue-gray agate)
Cryptocrystalline quartz, SiO₂; chalcedony/agate variety
Pumice
Pumice (Amorphous volcanic glass)
Pumice
Pumice (Amorphous volcanic glass)
Pumice
Pumice (Vesicular volcanic glass)
Pumice
Pumice (volcanic glass froth)
Red Quartzite
Quartzite (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Milky quartz with iron-stained matrix
Quartz (silicon dioxide, SiO₂)
Quartz Pebbles
Silicon Dioxide (SiO2)
Pumice
Pumice (a vesicular volcanic glass)
Pumice
Pumice (Amorphous volcanic glass)
Pumice
Pumiceous rhyolite / Volcanic glass
Pumice
Pumice (Vesicular volcanic glass)
Sandstone (Quartzite-rich)
Clastic sedimentary rock (primarily SiO2)
Quartz Pebble
Crystalline Silica (SiO2)
Quartzite
Quartzite (primarily SiO2)
Polished brown stone, likely smoky quartz or jasper
Tentatively quartz (SiO₂), possibly smoky quartz; exact identification requires testing
Likely weathered quartz-bearing rock fragment
Indeterminate; appears to contain quartz (SiO₂) with iron-oxide staining, possibly from quartzite, granite, or pegmatite
Tektite (Indochinite)
Tektite (Terrestrial Impact Glass)
Milky quartz (likely quartzite or massive quartz)
Quartz, silicon dioxide (SiO₂)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Grey Quartz (likely Smoky Quartz or Milky Quartz)
Silicon Dioxide (SiO2)