Fossiliferous limestone with colonial coral
Calcite (CaCO₃) limestone containing fossil tabulate or rugose coral colonies
Category
Browse anthropogenic material (man made sedimentary mimic) specimens identified by the Rock Identifier community.
Fossiliferous limestone with colonial coral
Calcite (CaCO₃) limestone containing fossil tabulate or rugose coral colonies
Conglomerate
Clastic Sedimentary Rock (Conglomerate)
Opalite
Man-made Glass (Synthetic Opalized Glass)
Crackle Agate / Dyed Quartz
SiO2 (Silicon Dioxide)
Synthetic Resin / Plastic Figurine
Synthetic Polymer (Copolymer of Polyethylene or Resin)
Bouncy Ball (Synthetic Rubber Polymer)
Polybutadiene / Ethylene Vinyl Acetate (EVA)
Cultured Marble (Synthetic)
Polymer-matrix composite (typically calcium carbonate in polyester resin)
Sea Glass
Silicon dioxide (mostly)
Sandstone Concretion
Clastic Sedimentary Concretion (typically Quartz/Silica with Iron Oxide)
Chert (often called Flint in archaeological contexts)
Microcrystalline or cryptocrystalline Silica (SiO2)
Concretion
Sedimentary Concretion (Ironstone / Calcite Concretion)
Dyed Agate
Chalcedony (SiO2)
Sandstone Concretion
Sedimentary Clastic Rock (Silicate-rich)
Tumbled clear quartz (rock crystal)
Quartz, silicon dioxide (SiO₂)
Tumbled milky quartz pebble
Quartz (silicon dioxide, SiO₂), likely milky quartz
Asphalt Chunk
Asphalt concrete
Chakra Stone (Composite / Man-made Bonded Gemstones)
Composite of Quartz, Lapis Lazuli, Aventurine, Tiger's Eye, and Jasper (SiO2, (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, etc.)
Likely tumbled or cut quartz/chalcedony fragment
Silicon dioxide (SiO₂), probably microcrystalline quartz or quartz
Opalite
Man-made Synthetic Glass (Silicon Dioxide with metal additives)
Blue opalite glass (likely man-made)
Opalite glass; a silica-based amorphous glass, not natural opal
Polished labradorite sphere
Labradorite, calcic plagioclase feldspar ((Ca,Na)(Al,Si)₄O₈)
Citrine Quartz
Citrine (Silicon Dioxide, SiO2)
Pet Rock (Man-made Quartzite or Granite Cobble)
Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica
Opalite (likely man-made opalescent glass)
Opalite; not a true mineral, typically synthetic opalescent glass (silica-based)
Diamond / Clear Quartz / Glass paste
Carbon (Diamond) / Silicon Dioxide (Quartz)
Goldstone
Aventurine glass (Synthetic glass with copper inclusions)
Unidentified translucent crystal/mineral fragment
Likely quartz (SiO₂), but visual identification is uncertain
Opalite
Synthetic Glass (Simulated Opal)
Magnetic Hematite (Man-made)
Iron Oxide (Fe2O3) with Barium-Strontium Ferrite
Goldstone
Aventurine Glass (Man-made glass with copper inclusions)
Aura Quartz
Titanium-coated Silicon Dioxide (SiO2)
Man-made Synthetic Material (Plastic/Composite)
Acrylonitrile Butadiene Styrene (ABS) or High-Impact Polystyrene (HIPS)
Slag Glass
SiO2 (Silicon Dioxide) with impurities
Opalite (likely imitation opal glass)
Man-made opalescent glass; not a natural mineral (often sold as opalite)
Sandstone Concretion
Septarian or Carbonate-cemented Sandstone Concretion
Chert (Arrowhead Artifact)
Microcrystalline Quartz (SiO2)
Small greenish crystal/mineral fragment
Indeterminate; possibly olivine, quartz, or a green gemstone fragment
Opalite (Synthetic Opalized Glass)
Synthetic Silicon Dioxide (SiO2) glass
Opalite crescent pendant
Opalite (man-made opalescent glass; not a natural mineral)
Opalite
Synthetic Opalite Glass / Opalized Glass
Carborundum (Silicon Carbide)
Silicon carbide (SiC)
Blue Impression Jasper beads
Impression jasper (microcrystalline quartz/chalcedony), chiefly SiO₂, with iron-oxide and other mineral inclusions