Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Category
Mineral (Man Made Glass)
Browse mineral (man made glass) specimens identified by the Rock Identifier community.
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Green Quartzite
Metamorphic Quartzite (often colored by chromium-bearing minerals or fuchsite)
metamorphic
Tumbled yellow jasper or chalcedony
Microcrystalline quartz, SiO₂; likely iron-oxide-bearing jasper/chalcedony
mineral
Weathered iron-rich rock, possibly jasper or ironstone
Likely limonite/goethite-bearing siliceous rock; exact identification requires hardness and streak tests
mineral
Black stone bead bracelet
Likely black tourmaline (schorl), though identification is uncertain from the image
mineral
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
igneous
Obsidian
Volcanic Glass (Amorphous SiO2)
igneous
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Slag Glass (Cullet)
Amorphous Silica / Glass residue
Man-made byproduct (Non-geological)
Diamond (in a cluster setting)
Crystallized Carbon (C)
mineral
Obsidian
Volcanic glass
igneous
Note on Image Identification: Textile
N/A (Anthropogenic material)
not a rock
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Carved smoky quartz (likely)
Quartz, silicon dioxide (SiO₂), smoky variety
mineral
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Black tourmaline bead bracelet (likely schorl)
Schorl, NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄
mineral
Amethyst (or Light Amethyst / Rose Quartz)
Quartz (Silicon Dioxide, SiO2)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Diamond
Diamond (pure native carbon, C)
mineral
Sandstone (likely Fossiliferous)
Arenite / Fossiliferous Sandstone (SiO2 composition)
sedimentary
Chert (and/or Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Carved labradorite fish
Labradorite, calcium-rich plagioclase feldspar (approximately (Ca,Na)(Al,Si)₄O₈)
mineral
Diamond Druzy (Crystalline Diamond)
Carbon (C)
mineral
Diamond (Cut jewelry specimen)
Diamond (pure Carbon, C)
mineral
Blue Quartz (Aventurine)
Silicon Dioxide (SiO2) with fibrous inclusions (commonly Dumortierite)
mineral
Amethyst
Silicon Dioxide (SiO2) with Fe3+ impurities
mineral
Obsidian
Volcanic glass (SiO2)
igneous
Turquoise (likely stabilized or simulated Howlite)
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
mineral
Amethyst Cluster
Silicon Dioxide with Iron impurities (SiO2)
mineral
Tumbled purple quartz, likely amethyst or lavender quartz
Quartz (SiO₂), probably iron-colored amethyst; exact variety uncertain from the image
mineral
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide)
igneous
Milky quartz
Quartz, silicon dioxide (SiO₂)
mineral
Smoky Quartz
Smoky Quartz (Silicon Dioxide, SiO2)
mineral
Grey Chalcedony
Silicon Dioxide (SiO2)
mineral
Diamond (as featured in jewelry)
Diamond (C - pure carbon)
mineral
Weathered concrete or cementitious slab (not natural rock)
Artificial calcium-silicate cement composite; likely Portland cement concrete
sedimentary
Black tourmaline bead bracelet, possibly mixed with smoky quartz or brown tourmaline
Schorl tourmaline, NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄; exact beads cannot be confirmed visually
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Chert
Chert (Microcrystalline Quartz)
sedimentary
Green obsidian (likely moldavite)
Natural volcanic glass; if extraterrestrial-impact glass, moldavite (tektite)
gemstone
Tumbled chalcedony (likely agate or jasper fragment)
Microcrystalline quartz, SiO₂ (chalcedony)
mineral
Natural or Cultured Pearl
Calcium Carbonate (Aragonite and Conchiolin), CaCO3
Mineral (Organic)