Chert (Yellow Jasper)
Cryptocrystalline Quartz (SiO2)
sedimentary
Category
Anthropogenic Material
Browse anthropogenic material specimens identified by the Rock Identifier community.
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Conglomeratic gravel / polymictic breccia
Polymictic rudite, likely anthropogenic or beach/stream gravel; composition varies
sedimentary
Nutting Stone / Cupstone (Sandstone or Quartzite)
Sedimentary rock with anthropogenic modification (cupule)
sedimentary
Synthetic Costume Accessory (Non-Geological)
Polyester and Acrylic Fiber (Anthropogenic polymer)
Synthetic / Man-made textile
Iron Slag
Anthropogenic Iron oxide/Silicate composite
Mineral-like byproduct (Technogenic)
Iron Slag
Anthropogenic Vitreous Silicate (Byproduct of Smelting)
Mineral-like byproduct
Crackled Quartz (Blue Dyed)
Silicon Dioxide (SiO2) with anthropogenic dye
mineral
Chert (Arrowhead or Flake)
Microcrystalline quartz (SiO2)
sedimentary
Asphalt (Bituminous pavement)
Bituminous concrete / Asphalt
Sedimentary (Anthropogenic)
Chert (Arrowhead Fragment)
Microcrystalline Quartz (SiO2)
sedimentary
Sea Glass
Amorphous Silicon Dioxide (Man-made glass weathered by nature)
mineral
Chert (Arrowhead artifact)
Chert (Cryptocrystalline Silica, SiO2)
sedimentary
Painted River Rock
Anthropogenic-modified Siliciclastic Sedimentary Rock
Sedimentary
Sea Glass
Amorphous Silica (Anthropogenic glass) - SiO2
mineral
Cullet (Slag Glass)
Amorphous Silica (SiO2) with various metal oxide colorants
mineraloid / anthropogenic
Conglomerate (Asphaltic/Anthropogenic)
Clastic sedimentary rock / Bituminous mixture
sedimentary
Chert (Arrowhead Fragment)
Silicon Dioxide (SiO2)
sedimentary
Sea Glass
Man-made silicate glass
sedimentary
Chert Arrowhead (Lithic Artifact)
Microcrystalline Quartz (SiO2)
sedimentary
Ferrochrome Slag
Anthropogenic silicate/oxide glass (Complex silicate matrix with Cr-Fe-Si inclusions)
Industrial byproduct (often confused with igneous rocks or meteorites)
Green Slag Glass
Amorphous Silicon Dioxide (with metallic impurities)
Igneous (Anthropogenic)
Slag
Ferrous slag (by-product of iron smelting)
Mineraloid / Anthropogenic
Likely weathered metallic mineral or slag fragment
Uncertain; possibly limonite/goethite-coated iron mineral, or industrial iron slag
mineral
Basalt
Basalt (Mafic volcanic rock)
igneous
Chert (Arrowhead/Projectile Point)
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Obsidian Arrowhead
Obsidian (Volcanic Glass)
igneous
Titanium Aura Quartz (Bismuth-coated Druzy)
Silicon Dioxide (SiO2) with Titanium/Metal vapor coating
mineral
Slag
Anthropogenic Vitreous Silicate / Ferro-silicate Slag
igneous
Painted River Pebble (likely Basalt or Greywacke)
Aphanitic Lithic Clast with Anthropogenic Pigment coating
Sedimentary or Igneous
Chert (Arrowhead Debitage or Flake)
Microcrystalline silica (SiO2)
sedimentary
Possible tektite or volcanic glass specimen
Natural silica glass; composition commonly near SiO₂, but exact identification requires chemical testing
mineral
Chert (Arrowhead variety)
Chert (SiO2)
sedimentary
Metal Chain (Likely Steel or a Steel Alloy)
Steel (primarily iron and carbon); specific alloy unknown
Man-made Object (Metal/Alloy)
Ferrochrome Slag
Anthropogenic slag (Fe-Cr alloy waste)
industrial byproduct
Slag (Industrial Glass)
Anthropogenic Vitreous Slag (Post-industrial byproduct)
igneous
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Greenstone Celt (Polished Stone Axe)
Metamorphosed mafic rock (often Basalt or Diabase)
metamorphic
Blue slag glass / industrial smelter slag
Man-made iron-rich silicate slag; composition variable, commonly Fe–Ca–Mg–Al silicates with glassy phases
mineral
Concrete Rubble with Aggregate
Hardened Portland Cement Paste with Coarse Aggregate
Anthropogenic (Man-made)
Granite Pebble
Granite (Phaneritic intrusive igneous rock comprising Quartz, Feldspar, and Mica)
igneous
Green sea glass or green glass-like tumbled material
Amorphous silicate glass; likely anthropogenic soda-lime glass, not a natural mineral
mineral
Banded Slag Glass (Leland Blue/Frankfort Green style)
Anthropogenic Glass Specimen (Amorphous Silicon Dioxide with impurities)
mineral