Possible obsidian or slag glass
Volcanic glass, primarily SiO₂; alternatively industrial iron-rich glassy slag
Category
Browse man made composite (lithified equivalent of sedimentary) specimens identified by the Rock Identifier community.
Possible obsidian or slag glass
Volcanic glass, primarily SiO₂; alternatively industrial iron-rich glassy slag
Fluorite (Polished Point/Tower)
Calcium Fluoride (CaF2)
Stone Mosaic Mask
Composite silicate and carbonate minerals
Sea Glass
Amorphous silicon dioxide (SiO2) - Man-made glass tumbled by nature
Blue Goldstone
Man-made glass with suspended copper, cobalt, or manganese particles
Clear quartz tumbled stone
Quartz (silicon dioxide, SiO₂)
Aura Quartz
Titanium-coated Silicon Dioxide (SiO2)
Ferrochrome Slag
Anthropogenic slag (Fe-Cr alloy waste)
Goldstone (Red)
Aventurine Glass (Cupriferous glass)
Blue-dyed tumbled quartz or glass imitation
Quartz (SiO₂), appearance possibly enhanced with blue dye; identity uncertain from image
Cubic Zirconia (Simulated Diamond)
Cubic Zirconia (ZrO2)
Opalite
Synthetic Opalized Glass
Blue Glass or Slag Glass
Amorphous Silica (Anthropogenic Glass)
Black glassy fragment, likely obsidian or industrial glass
Volcanic glass (obsidian), chiefly amorphous SiO₂; identification uncertain from image
Blue obsidian-like volcanic glass
Volcanic glass, chiefly silica-rich amorphous material (composition uncertain)
Milky quartz (likely quartz crystal fragment)
Quartz, silicon dioxide (SiO₂)
Pet Rock (Man-made Quartzite or Granite Cobble)
Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica
Hematite Beads
Hematite (Fe2O3)
Asphalt
Asphalt concrete (engineered material, not a naturally occurring rock/mineral in this form)
Polished black stone, likely black obsidian
Obsidian (volcanic glass), chiefly silica-rich rhyolitic composition
Pink Tumbled Quartz (Dyed)
Silicon Dioxide (SiO2)
Dyed Crackle Quartz (Green)
Quenching-treated Quartz (Silicon Dioxide, SiO2)
Slag Glass
SiO2 (Silicon Dioxide) with impurities
Opalite
Synthetic Glass, SiO2 base with metallic inclusions
Goldstone (Brown/Gold variety)
Aventurine Glass (SiO2 with Copper inclusions)
Blue Goldstone
Goldstone (artificial glass)
Black Obsidian
Amorphous volcanic glass (SiO2 + impurities)
Green sea glass or tumbled green quartz (uncertain)
Likely quartz (SiO₂) if natural; alternatively man-made soda-lime glass
Man-made Jewelry (Metal and Glass/Plastic)
Synthetic Alloy and Amorphous Solid (SiO2/Polymer)
Green obsidian (likely molded or heat-treated glass-like specimen)
Volcanic glass; predominantly rhyolitic composition (silica-rich amorphous SiO₂)
Polished white calcite sphere (identification tentative)
Calcite, CaCO₃
Green sea glass (likely bottle glass)
Man-made soda–lime silicate glass; not a natural mineral
Sea Glass
Amorphous silicon dioxide (Man-made glass weathered by nature)
Aura Quartz (Titanium/Gold coated)
Silicon Dioxide (SiO2) with metallic vapor deposition
Polished white chalcedony or quartz pendant
Microcrystalline quartz (chalcedony), SiO₂; exact identification is uncertain from the image
Iron Slag
Iron/Steel Slag (Ferrosilicate Glass)
Iron Slag (Industrial Byproduct)
Anthropogenic Vitrification Product/Ferrous Slag
Polished black stone, likely obsidian
Obsidian (volcanic glass; mostly silica-rich rhyolitic composition)
Blue opal heart cabochon
Common opal, hydrated amorphous silica (SiO₂·nH₂O), likely blue-dyed or synthetic opalite
Slag (Industrial Glass/Glassy Rock)
Anthropogenic Vitreous Material
Sea Glass (White/Clear)
Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO
Aura Quartz
Titanium/Titanium-Gold treated Silicon Dioxide (SiO2)