Tumbled opalite (likely man-made glass)
Opalite glass; a synthetic opalescent glass, not a natural mineral species
Category
Browse anthropogenic material (man made sedimentary mimic) specimens identified by the Rock Identifier community.
Tumbled opalite (likely man-made glass)
Opalite glass; a synthetic opalescent glass, not a natural mineral species
Obsidian (likely black volcanic glass)
Obsidian; primarily amorphous volcanic silica glass, approximately SiO₂-rich rhyolitic composition
Chert Arrowhead (Projectile Point)
Microcrystalline Quartz (SiO2)
Chert Arrowhead
Microcrystalline Quartz (SiO2)
Chert Concretion
Chert (Microcrystalline Quartz, SiO2)
Crescent Pebble
Weathered Quartzite or Sandstone Fragment
Green Obsidian Sphere (man-made glass)
Vitreous Silica with Chromium/Iron additives
Boxwork or Septarian Concretion
Septarian nodule / Boxwork weathering
Tumbled milky quartz (likely)
Quartz, silicon dioxide (SiO₂)
Black glassy fragment, likely obsidian or industrial glass
Volcanic glass (obsidian), chiefly amorphous SiO₂; identification uncertain from image
Sea Glass (White/Clear)
Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO
Faceted clear gemstone, likely quartz or glass imitation
Most likely quartz (SiO₂); exact identification requires refractive-index and hardness tests
Slag (Industrial Byproduct)
Anthropogenic Vitreous Silicate material
Green Sea Glass
Amorphous Silica (man-made glass), SiO2 + additive metal oxides
Mystic Topaz (Treated Quartz or Topaz)
Aluminum silicate fluoride hydroxide [Al2SiO4(F,OH)2] with thin-film metallic coating
Diamond
Carbon (C)
Opalite
Synthetic Opalite (Man-made glass)
Cullet Glass (Slag)
Amorphous Silicon Dioxide (Man-made)
Glazed Ceramic Tile
Fused Silicate-Clay composite
Polished black pebble, possibly obsidian
Volcanic glass (obsidian), likely; identification is tentative from the image
Pearl
Pearl (Calcium Carbonate with organic conchiolin, CaCO3)
Opalite (likely man-made glass)
Opalite; amorphous silica glass, not a natural mineral
Chert (Field-collected Arrowhead-shaped Fragment)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Green obsidian (likely molded or heat-treated glass-like specimen)
Volcanic glass; predominantly rhyolitic composition (silica-rich amorphous SiO₂)
Carborundum (Silicon Carbide)
Silicon Carbide (SiC)
Sandstone Anvil / Nutting Stone
Quartzose Sandstone (Sedimentary Rock)
Baked-clay ceramic fragment (likely brick or pottery)
Fired clay, primarily aluminosilicate minerals; not a natural rock
Chert (Arrowhead)
Microcrystalline Quartz (SiO2)
Polished black stone, likely black obsidian
Obsidian (volcanic glass), chiefly silica-rich rhyolitic composition
Milky quartz (rough fragment)
Quartz, silicon dioxide (SiO₂)
Tumbled milky chalcedony (likely common opalite-like quartz)
Chalcedony, microcrystalline SiO₂; possibly pale common opal, hydrated SiO₂·nH₂O
Clear quartz crystal (likely)
Quartz, silicon dioxide (SiO₂)
Titanium Aura Quartz
Titanium bonded Silicon Dioxide (SiO2 + Ti)
Polished white chalcedony or quartz pendant
Microcrystalline quartz (chalcedony), SiO₂; exact identification is uncertain from the image
Metal Alloy (Likely Pewter or Sterling Silver)
Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).
Goldstone (Red)
Aventurine Glass (SiO2 + Cu)
Blue opal heart cabochon
Common opal, hydrated amorphous silica (SiO₂·nH₂O), likely blue-dyed or synthetic opalite
Opalite
Synthetic Glass (Simulated Moonstone/Opal)
Clear Quartz Sphere (Rock Crystal)
Silicon Dioxide (SiO2)
Botryoidal chalcedony (likely agate/jasper variety)
Microcrystalline quartz, SiO₂
Aura Quartz (Titanium Quartz)
Titanium-coated Silicon Dioxide (SiO2 + Ti)
Chert Arrowhead
Microcrystalline Quartz (SiO2)