Sea Glass
Man-made silicate glass weathering product
sedimentary
Category
Anthropogenic Material
Browse anthropogenic material specimens identified by the Rock Identifier community.
Learn about Anthropogenic Material in the encyclopedia
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Chert (Arrowhead/Projectile Point)
Microcrystalline quartz (SiO2)
sedimentary
Conglomeratic gravel / polymictic breccia
Polymictic rudite, likely anthropogenic or beach/stream gravel; composition varies
sedimentary
Chert (specifically a Lithic Flake)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Green sea glass (likely bottle glass)
Human-processed soda–lime silicate glass; not a natural mineral or rock
mineral
Small dark mineral/rock fragment
Indeterminate; possibly magnetite-bearing basalt or iron-rich slag
mineral
Painted River Rock
Anthropogenic-modified Siliciclastic Sedimentary Rock
Sedimentary
Sea Glass
Amorphous Silica (Anthropogenic glass) - SiO2
mineral
Concrete Fragment
Hardened Portland cement and mineral aggregate
sedimentary (anthropogenic)
Chert (often called Flint)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Conglomerate (Asphaltic/Anthropogenic)
Clastic sedimentary rock / Bituminous mixture
sedimentary
Chert (Arrowhead or Flake)
Microcrystalline quartz (SiO2)
sedimentary
Slag (Industrial Glass)
Artificial Vitreous Silicate
mineraloid (anthropogenic)
Chert Arrowhead (Lithic Artifact)
Microcrystalline Quartz (SiO2)
sedimentary
Chert Arrowhead (Lithic Artifact)
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Chert Arrowhead
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert Arrowhead
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Arrowhead artifact)
Chert (Cryptocrystalline Silica, SiO2)
sedimentary
Asphalt (Bituminous pavement)
Bituminous concrete / Asphalt
Sedimentary (Anthropogenic)
Chert (Yellow Jasper)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Arrowhead Fragment)
Microcrystalline Quartz (SiO2)
sedimentary
Sea Glass
Amorphous Silicon Dioxide (Man-made glass weathered by nature)
mineral
Chert (Arrowhead Fragment)
Silicon Dioxide (SiO2)
sedimentary
Sea Glass
Man-made silicate glass
sedimentary
Ferrochrome Slag
Anthropogenic silicate/oxide glass (Complex silicate matrix with Cr-Fe-Si inclusions)
Industrial byproduct (often confused with igneous rocks or meteorites)
Chert Arrowhead (Lithic Artifact)
Microcrystalline Quartz (SiO2)
sedimentary
Cullet (Slag Glass)
Amorphous Silica (SiO2) with various metal oxide colorants
mineraloid / anthropogenic
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
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
Ferrochrome Slag
Anthropogenic slag (Fe-Cr alloy waste)
industrial byproduct
Slag (Industrial Glass)
Anthropogenic Vitreous Slag (Post-industrial byproduct)
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
Chert (Arrowhead variety)
Chert (SiO2)
sedimentary
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
Metal Chain (Likely Steel or a Steel Alloy)
Steel (primarily iron and carbon); specific alloy unknown
Man-made Object (Metal/Alloy)