Basalt
Basalt (Mafic volcanic rock)
igneous
Category
Industrial Byproduct (Anthropogenic Material)
Browse industrial byproduct (anthropogenic material) specimens identified by the Rock Identifier community.
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Green Quartz (Prasiolite or Aventurine)
Silicon Dioxide (SiO2)
mineral
Quartzite (Lithic Artifact)
Quartzite (SiO2)
metamorphic
Iron-rich slag or ironstone; appearance is not diagnostic
Likely iron-oxide-rich material (hematite, Fe₂O₃, and/or magnetite, Fe₃O₄); possibly smelting slag
mineral
Blue slag-like mineral specimen, possibly bornite or chalcopyrite
Tentatively bornite (Cu5FeS4) or iridescent chalcopyrite (CuFeS2)
mineral
Chert (Arrowhead/Projectile Point)
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Obsidian Arrowhead
Obsidian (Volcanic Glass)
igneous
Milky Quartz or Calcite Pebble
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)
mineral
Titanium Aura Quartz (Bismuth-coated Druzy)
Silicon Dioxide (SiO2) with Titanium/Metal vapor coating
mineral
Sulfur
Native Sulfur (S)
mineral
Sulfur (with Matrix)
Native Sulfur (S8)
mineral
Bismuth Crystal
Bismuth (Bi)
mineral
Chert (Arrowhead variety)
Chert (SiO2)
sedimentary
Silver Nuggets (Natural or Cast)
Native Silver (Ag)
mineral
Arsenopyrite with Schist Matrix
Arsenopyrite (FeAsS)
mineral
Chert (Arrowhead Debitage or Flake)
Microcrystalline silica (SiO2)
sedimentary
Tiffany Stone
Fluoritized Opal Beryllium Tuff (composed of Fluorite; CaF2, Opalized SiO2, Bertrandite, Chalcedony, and Quartz)
metamorphic
Greenstone Celt (Polished Stone Axe)
Metamorphosed mafic rock (often Basalt or Diabase)
metamorphic
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Fluorite (Fluor-spar)
Calcium Fluoride (CaF2)
mineral
Fluorite (Purple/Blue variety)
Calcium Fluoride (CaF2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Possible basaltic volcanic rock or iron-rich meteorite
Likely basalt (plagioclase–pyroxene rock); meteorite status cannot be confirmed visually
igneous
Chalcopyrite
Chalcopyrite (CuFeS2)
mineral
Cullet Glass (Industrial Slag Glass)
Amorphous Silica (SiO2) with metallic oxide impurities
Man-made byproduct (often mistaken for Obsidian or Emerald)
Silver (Sterling Silver Jewelry)
Argentum (Ag) mixed with Copper (Cu)
mineral
Diamond (or Diamond Simulant)
C (Carbon) or synthetic equivalent
gemstone
Granite Pebble
Granite (Phaneritic intrusive igneous rock comprising Quartz, Feldspar, and Mica)
igneous
Concrete Rubble with Aggregate
Hardened Portland Cement Paste with Coarse Aggregate
Anthropogenic (Man-made)
Silver (Jewelry form)
Native Silver (Ag)
mineral
Chert Arrowhead
Cryptocrystalline microcrystalline Quartz (SiO2)
sedimentary
Calcite
Calcium Carbonate (CaCO3)
mineral
Diamond (or Simulant)
Carbon (C) or relevant simulant formula (e.g., ZrO2 for Cubic Zirconia)
gemstone
Pyrite (on Quartz matrix)
Iron Disulfide (FeS2)
mineral
Diamond (or diamond simulant)
C
gemstone
Tumbled dark stone, likely basalt or gabbro
Basalt (fine-grained mafic rock), possibly gabbro; mainly plagioclase and pyroxene
igneous
Asphalt (Road Aggregate)
Asphalt concrete / Bituminous mixture
anthropogenic sedimentary (technolith)
Possible meteorite fragment
Undetermined; likely an iron-rich meteorite or meteorite-like slag fragment
meteorite
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Diamond (or Diamond Simulant)
Carbon (C)
gemstone
South Korean 100 Won Coin (Cupronickel)
Cupronickel Alloy (75% Cu, 25% Ni)
mineral-based alloy (anthropogenic)