Obsidian
Volcanic Glass
Category
Browse anthropogenic (man made) specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass
Blue Obsidian
Volcanic Glass (Amorphous)
Diamond (or Simulant)
Carbon (C)
Blue Goldstone
Man-made glass infused with copper crystals
Synthetic Faux Fur Fursuit
Polyacrylonitrile / Polyester (Synthetic Textile)
Blue opalescent glass-like gemstone (possibly imitation opalite)
Likely man-made opalite glass; composition varies, typically silica-based glass
Sea Glass
Silicon dioxide (mostly)
Blue crystal pendant (likely blue glass or synthetic crystal)
Not identifiable from the image; possibly synthetic quartz or glass, rather than a natural mineral
Quartz pebble (Quartztite fragment)
Silicon Dioxide (SiO2)
Small black stone fragment (possibly obsidian)
Unidentified dark rock; obsidian is volcanic glass (composition typically rhyolitic)
Obsidian
Volcanic Glass
Concrete with Aggregate
Composite construction material; primary matrix is Calcium Silicate Hydrate (C-S-H)
Pet Rock (Man-made Quartzite or Granite Cobble)
Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica
Cobalt Blue Glass / Cullet Glass
Silicon dioxide (Amorphous man-made glass)
Chert (Arrowheads)
Microcrystalline Quartz (SiO2)
Goldstone
Man-made glass with copper inclusions
Asphalt (Bituminous Concrete)
Bituminous mix / Anthropogenic conglomerate
Exposed Aggregate Concrete (Pea Gravel)
Concrete with Siliceous Alluvial Gravels
Asphalt Concrete
Bituminous Concrete / Asphaltic Composite
Opalite
Synthetic Opalite Glass / Opalized Glass
Asphalt Concrete
Bituminous conglomerate
Cullet Glass (Slag Glass)
Amorphous Silicon Dioxide (SiO2) with metallic oxide impurities
Green Obsidian Sphere (man-made glass)
Vitreous Silica with Chromium/Iron additives
Opalite
Synthetic Opalite (Man-made glass)
Opalite
Man-made Glass (SiO2 + additives)
Goldstone
Man-made glass with copper inclusions
Cullet Glass (Slag)
Amorphous Silicon Dioxide (Man-made)
Green Sea Glass
Man-made silicate glass (weathered)
Chert Arrowhead
Microcrystalline Quartz (SiO2)
Likely iron-rich slag or weathered ironstone fragment
Uncertain; possibly iron oxide–rich material (hematite/goethite) or industrial iron slag
Blue-green faceted gemstone, possibly glass or synthetic material
Not identifiable from the image; possible synthetic spinel or glass
Asphalt (Road Aggregate)
Bituminous conglomerate
Crushed Stone (Likely Limestone or Granite)
Calcium Carbonate (CaCO3) for Limestone / Quartz and Feldspar for Granite
Mystic Topaz (Treated Quartz or Topaz)
Aluminum silicate fluoride hydroxide [Al2SiO4(F,OH)2] with thin-film metallic coating
Sandstone Concretion
Limonitic Sandstone Concretion
Terrazzo (Man-made Composite)
Cementitious or Resin-bound Lithic Composite
Faceted clear gemstone in a gold-colored setting
Unidentified transparent faceted stone; possibly quartz, glass, or another colorless gem
Concrete Paver (Artificial Cementitious Rock)
Hydrated Portland Cement Aggregate
Unidentifiable Rock Fragment
Obsidian
Volcanic glass
Cullet Glass (Slag Glass)
Amorphous Silicon Dioxide (Industrial Man-made)
Sea Glass
Amorphous silicon dioxide (Man-made glass weathered by wave action)