Black Obsidian
Amorphous volcanic glass (SiO2 + impurities)
Category
Browse antropogenic rock (man made) specimens identified by the Rock Identifier community.
Black Obsidian
Amorphous volcanic glass (SiO2 + impurities)
Blue goldstone beads
Man-made aventurine glass (silica glass with metallic copper inclusions), not natural lapis lazuli
Green obsidian (likely molded or heat-treated glass-like specimen)
Volcanic glass; predominantly rhyolitic composition (silica-rich amorphous SiO₂)
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)
Polished black stone, likely obsidian
Obsidian (volcanic glass; mostly silica-rich rhyolitic composition)
Terrazzo (with Marble and Granite fragments)
Cementitious or resinous composite containing Calcium Carbonate (CaCO3) and Silicates
Green sea glass or tumbled green quartz (uncertain)
Likely quartz (SiO₂) if natural; alternatively man-made soda-lime glass
Aura Quartz
Titanium/Titanium-Gold treated Silicon Dioxide (SiO2)
Polished white calcite sphere (identification tentative)
Calcite, CaCO₃
Botryoidal chalcedony (likely agate/jasper variety)
Microcrystalline quartz, SiO₂
Polished silver sheen obsidian heart
Obsidian (volcanic glass), primarily rhyolitic silica-rich glass
Blue-green cabochon, likely chalcedony or treated glass imitation
Cryptocrystalline quartz (chalcedony/possibly chrysoprase); identification uncertain from image
Opalite
Synthetic Opalised Glass
Carborundum (Silicon Carbide)
Silicon Carbide (SiC)
Red-orange cabochon, likely carnelian or glass imitation
Carnelian: chalcedony (microcrystalline SiO₂), commonly iron-colored
Polished black pebble, possibly obsidian
Volcanic glass (obsidian), likely; identification is tentative from the image
Sea Glass
Amorphous silicon dioxide (Man-made glass weathered by nature)
Blue glassy tumbled stone, likely blue chalcedony or slag glass
Chalcedony (microcrystalline SiO₂), possibly man-made blue glass
Sea Glass
Amorphous Silicon Dioxide (Man-made glass weathered by nature)
Vesicular basalt (weathered scoria)
Scoriaceous basalt; chiefly plagioclase, clinopyroxene, olivine, and iron-titanium oxides
Tumbled milky quartz
Quartz (silicon dioxide, SiO₂)
Titanium Amethyst Geode
Silicon Dioxide (SiO2) with Titanium/Metal Vapor Deposition Layer
Green Glass (often marketed as 'Obsidian' or 'Green Quartz')
Amorphous Silica (SiO2) with copper or chromium additives
Milky quartz (rough fragment)
Quartz, silicon dioxide (SiO₂)
Hematite
Iron(III) oxide (Fe2O3)
Goldstone (Red)
Aventurine Glass (SiO2 + Cu)
Ferro-slag (Leland Blue/Slag Glass)
Anthropogenic Vitreous Silica (Industrial Slag)
Goldstone (blue/black aventurine glass)
Man-made aventurine glass; silica glass containing metallic copper or other glittering inclusions
Blue Crackle Quartz (Dyed Quarzite)
Silicon Dioxide (SiO2) with artificial dye
Dyed Blue Agate (Dragon Vein Agate)
Silicon Dioxide (SiO2) with artificial cobalt/organic dyes
Diamond
Native Carbon (C)
Dyed Aura Quartz
Silicon Dioxide (SiO2) with metallic coating
Cullet Glass (sometimes mistaken for Blue Obsidian or Slag)
Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)
Red-orange jasper pebble (tentative)
Microcrystalline quartz, SiO₂, colored mainly by iron oxides
Opalite
Synthetic glass (SiO2 + metal additions)
Blue chalcedony (likely dyed or treated)
Microcrystalline quartz, SiO₂ (chalcedony)
Slag Glass (Leland Blue variant)
Anthropogenic Vitreous Silicate
Raw quartz crystal
Quartz (silicon dioxide, SiO₂), likely milky or included quartz
Metallic sulfide mineral fragment, likely galena
Galena (lead sulfide, PbS), tentative identification
Tumbled milky chalcedony (likely common opalite-like quartz)
Chalcedony, microcrystalline SiO₂; possibly pale common opal, hydrated SiO₂·nH₂O