Basalt (River Pebble)
Extrusive Mafic Igneous Rock
Category
Browse man made glass (not a natural rock or mineral) specimens identified by the Rock Identifier community.
Basalt (River Pebble)
Extrusive Mafic Igneous Rock
Chert (Iron-stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Sandstone
Arenite (primarily SiO2)
Red Sandstone
Arenite (with Iron Oxide / Hematite staining)
Quartz Pebble (Hag Stone / Adder Stone)
Silicon Dioxide (SiO2)
Dyed Quartzite
Tumbled Metamorphosed Quartz (SiO2) with artificial pigment
Libyan Desert Glass
Tektite (high-silica impact glass), SiO2 + tracing minerals
Granite
Phaneritic high-silica plutonic rock (composed primarily of Quartz, Feldspar, and Mica)
Quartz (variety of colors)
SiO2 (Silicon Dioxide)
Mahogany Obsidian
Obsidian (Volcanic Glass) with Hematite or Magnetite inclusions, SiO2 (Silicon Dioxide)
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions
Yellow Quartz
Silicon Dioxide (SiO2)
Quartz / Quartzite
Silicon Dioxide (SiO2)
Chalk
CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock
Quartz (Milky/Granular)
Silicon Dioxide (SiO2)
Massive Quartz (Milky or Gray)
Silicon Dioxide (SiO2)
Green Aventurine
Quartz (SiO2) with Fuchsite inclusions
Sandstone
Arenite (SiO2 based)
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
Grey River Pebble (Likely Quartz-rich or Limestone)
Clastic Sedimentary Rock (typically SiO2 or CaCO3 based)
Sandstone
Arenite (SiO2 principal component)
Diamond
Carbon (C)
Milky Quartz
Silicon Dioxide (SiO2)
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Quartz (River Pebble)
Quartz (SiO₂ - Silicon Dioxide)
Dyed Agate Slice
Silicon Dioxide (SiO2) with artificial colorants
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
Citrine Quartz
Crystalline Silicon Dioxide (SiO2) with Ferric Iron impurities
Citrine Quartz
Silicon Dioxide (SiO2) - Ferric Iron impurities
Citrine (Quartz variant)
SiO2 (Silicon Dioxide)
Blue Topaz
Topaz [Al2SiO4(F,OH)2]
Sea Glass (Frosted Glass)
Amorphous Silica (SiO2) with various metal oxide impurities
Sandstone
Arenite (primarily SiO2)
Yellow Quartz (Citrine-colored Quartz Pebble)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Granite
Granite (Felsic Plutonic Rock)
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Milky Quartz with Mineral Inclusions
Silicon Dioxide (SiO2) with miscellaneous inclusions
Greywacke (River Siltstone)
Lithic Wacke (Sandstone subfamily)
Sandstone
Arenite (SiO2 primarily)