Anthracite Coal with Sulfur staining
Anthracite (Carbon C with impurities)
metamorphic
Category
Industrial Byproduct (Anthropogenic Rock)
Browse industrial byproduct (anthropogenic rock) specimens identified by the Rock Identifier community.
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Chert Arrowhead (Lithic Artifact)
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Chert Arrowhead
Cryptocrystalline Quartz (SiO2)
sedimentary
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Iron-rich vesicular rock, possibly slag or weathered basalt
Identification uncertain; likely ferruginous basalt/ironstone, with possible anthropogenic iron slag
igneous
Chert (Arrowhead artifact)
Chert (Cryptocrystalline Silica, SiO2)
sedimentary
Asphalt Conglomerate
Artificial Bituminous Conglomerate
sedimentary
Chert Arrowhead (Lithic Artifact)
Microcrystalline Quartz (SiO2)
sedimentary
Silicon Carbide
Silicon Carbide (Moissanite / Carborundum), SiC
mineral
Cullet Glass / Slag Glass
Amorphous silica glass
man-made glass / industrial byproduct
Asphalt Concrete
Bituminous Concrete (Anthropic Rock)
sedimentary
Chert (Arrowhead Debitage or Spall)
Silicon Dioxide (SiO₂)
sedimentary
Small dark mineral/rock fragment
Indeterminate; possibly magnetite-bearing basalt or iron-rich slag
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Painted River Rock
Artificially Coated Sedimentary Rock
sedimentary
Sandstone (likely Fossilized Wood or Concrete Simulacrum)
Arenite / Silicified Wood / Anthropogenic Concrete
sedimentary
Concrete
Anthropogenic Sedimentary Rock (Hydrated Calcium Silicate)
sedimentary (anthropogenic / man-made)
Basalt
Basalt (Mafic volcanic rock)
igneous
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Slag (Industrial Glass Slag)
Amorphous Silicate Glass (often containing Al, Ca, Mg, and Ti oxides)
Mineraloid (Industrial byproduct)
Chert Arrowhead (Lithic Tool)
Microcrystalline quartz (SiO2) - Archeological lithic artifact
sedimentary
Green sea glass (likely bottle glass)
Human-processed soda–lime silicate glass; not a natural mineral or rock
mineral
Green Slag Glass
Amorphous Silica / Glassy Blast Furnace Slag
Mineraloid (Industrial byproduct)
Sea Glass
Man-made silicate glass
mineral
Possible tektite or volcanic glass specimen
Natural silica glass; composition commonly near SiO₂, but exact identification requires chemical testing
mineral
Jasper (Multi-colored) / Sea Glass Slag
Silicon Dioxide (SiO2) with impurities of Iron Oxide
Sedimentary (if natural Jasper) or Artificial (if Slag)
Blue Sea Glass
Amorphous Silica (Anthropogenic glass)
not a rock (man-made origin)
Cullet Glass (sometimes mistaken for Blue Obsidian or Slag)
Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)
mineraloid / industrial byproduct
Metal Chain (Likely Steel or a Steel Alloy)
Steel (primarily iron and carbon); specific alloy unknown
Man-made Object (Metal/Alloy)
Obsidian Arrowhead
Obsidian (Volcanic Glass)
igneous
Quartz (Engineered Quartz Surface)
Silicon Dioxide (SiO2) based composite
mineral (man-made composite)
Possible iron meteorite
Metallic meteorite, likely Fe–Ni alloy (kamacite/taenite)
meteorite
Red Slag Glass (Cullet)
Amorphous Silicon Dioxide (SiO2) with metallic dopants
Antropogenic (Man-made material)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Sea Glass
Anthropogenic Silicate Glass
mineral
Iron-rich slag or weathered ironstone fragments
Probably hematite–goethite material; possibly industrial iron slag (Fe₂O₃/FeO(OH))
mineral
Slag
industrial by-product
Possible industrial slag or basaltic volcanic glass
Likely iron-rich vitreous slag; natural alternative: basaltic glass (tachylite)
igneous
Ferruginous Conglomerate (or Iron-Rich Concrete/Slag)
Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)
sedimentary
Asphalt (Bituminous pavement)
Bituminous concrete / Asphalt
Sedimentary (Anthropogenic)
Sea Glass
Man-made vitreous material (silica-based glass)
mineral
Slag Glass
Glassy Silicate Residue
industrial byproduct