Stainless Steel (Polished)
Ferrous Alloy containing Iron (Fe), Chromium (Cr), and Carbon (C)
Category
Browse mineraloid (man made glass) specimens identified by the Rock Identifier community.
Stainless Steel (Polished)
Ferrous Alloy containing Iron (Fe), Chromium (Cr), and Carbon (C)
Quartz (likely milky quartz or quartz glass-like fragment)
Quartz, silicon dioxide (SiO₂)
Goldstone (Brown)
Aventurine glass
Opalite crescent pendant
Opalite (man-made opalescent glass; not a natural mineral)
Blue Glass or Slag Glass
Amorphous Silica (Anthropogenic Glass)
Slag Glass
Anthropogenic Amorphous Silicon Dioxide
Black tumbled stone, possibly obsidian
Obsidian (volcanic glass; predominantly SiO₂), identification uncertain from image
Libyan Desert Glass
Tektite (high-silica impact glass), SiO2
Sea Glass
Man-made vitreous material (silica-based glass)
Opalite
Synthetic Opalised Glass
Pearl (Biogenic Mineraloid)
Calcium carbonate (CaCO3) primarily as Aragonite
Tumbled clear quartz (rock crystal)
Quartz, silicon dioxide (SiO₂)
Precious Coral (Red Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
Sea Glass (White/Clear)
Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO
Chert (Arrowheads)
Microcrystalline Quartz (SiO2)
Libyan Desert Glass
Libyan Desert Glass (SiO2 with trace elements)
Clear quartz sphere
Quartz (silicon dioxide, SiO₂)
Clear quartz tumbled stone
Quartz (silicon dioxide, SiO₂)
Opalite (Man-made Glass)
Fused glass (typically made of dolomite and metal opacifiers)
Sea Glass
Man-made silicate glass (Amorphous silicon dioxide)
Strawberry Quartz
Silicon Dioxide (SiO2) with Hematite or Goethite inclusions
Obsidian (Blue)
Volcanic Glass (SiO2)
Blue cabochon gemstone, likely synthetic glass or dyed stone
Indeterminate from image; possible glass, synthetic spinel, sodalite, or lapis lazuli
Exposed Aggregate Concrete (Pea Gravel)
Concrete with Siliceous Alluvial Gravels
Tumbled milky quartz pebble
Quartz (silicon dioxide, SiO₂)
Moldavite
Tektite (Impact Glass), ~80% SiO2 + Al2O3
Blue glassy gemstone cabochon, likely dyed chalcedony or glass
Uncertain; possible dyed chalcedony (microcrystalline quartz, SiO₂)
Likely clear quartz pebble or glassy quartz fragment
Quartz (silicon dioxide, SiO₂)
Tumbled gray stone, likely quartz-rich pebble
Probable microcrystalline quartz/chalcedony (SiO₂), possibly gray jasper or quartzite
Concrete Fragment
Hardened Portland cement and mineral aggregate
Blue Obsidian (Cullet Glass)
Silicon Dioxide (Amorphous Glass)
Blue Goldstone
Man-made glass with suspended copper, cobalt, or manganese particles
Glass Nugget (Tumbled Glass)
Amorphous Silicon Dioxide (SiO2) with additives
Clear quartz fragment (rock crystal)
Quartz, silicon dioxide (SiO₂)
Decorative mosaic cross containing mixed rock and glass fragments
Polychrome aggregate; likely quartz, feldspar, marble, granite, and assorted colored glass
Asphalt Concrete
Bituminous conglomerate
Slag (Industrial Byproduct)
Artificial silicate/iron byproduct
Opalite
Man-made Synthetic Glass (Silicon Dioxide with metal additives)
Green sea glass or tumbled green quartz (uncertain)
Likely quartz (SiO₂) if natural; alternatively man-made soda-lime glass
Blue Goldstone
Aventurine Glass
Black glassy fragment, likely obsidian or industrial glass
Volcanic glass (obsidian), chiefly amorphous SiO₂; identification uncertain from image
Opalite
Synthetic Glass (Simulated Moonstone/Opal)