Small dark mineral/rock fragment
Indeterminate; possibly magnetite-bearing basalt or iron-rich slag
Category
Browse mineral byproduct (anthropogenic) specimens identified by the Rock Identifier community.
Small dark mineral/rock fragment
Indeterminate; possibly magnetite-bearing basalt or iron-rich slag
Orange Calcite
Calcium Carbonate (CaCO3)
Orange Calcite
Calcite (Calcium Carbonate, CaCO3)
Copper slag or vesicular basalt with copper minerals
Industrial slag / Basaltic matrix with secondary copper minerals
Possible flint or slag fragment
Microcrystalline quartz (chalcedony), or iron-rich industrial slag
Gold
Native Gold (Au)
Stainless Steel (Polished)
Ferrous Alloy containing Iron (Fe), Chromium (Cr), and Carbon (C)
Sandstone (likely Fossilized Wood or Concrete Simulacrum)
Arenite / Silicified Wood / Anthropogenic Concrete
Blue Obsidian (Cullet Glass)
Silicon Dioxide (Amorphous Glass)
Sea Glass
Amorphous Silicon Dioxide (Man-made glass weathered by nature)
Ferrosilicon Slag (Industrial Vitrified Glass)
Vitreous Silicate Residue
Fluorite (Fluor-spar)
Calcium Fluoride (CaF2)
Likely weathered iron-rich rock or slag fragment
Indeterminate; possibly limonite/goethite-bearing rock (FeO(OH)·nH₂O) or industrial iron slag
Chert Arrowhead
Cryptocrystalline Quartz (SiO2)
Blue Dyed Quartzite
Silicon Dioxide (SiO2) with artificial pigment
Mystic Topaz
Aluminum silicate fluoride hydroxide with titanium coating (Al2SiO4(F,OH)2)
Cupronickel (on a 1981 Mexico 20 Pesos coin)
Copper-Nickel Alloy (Cu75Ni25)
Cullet Glass (Slag)
Amorphous Silicon Dioxide (Man-made)
Blue Slag Glass
Amorphous Silica (Byproduct of smelting)
Bismuth
Bismuth (element Bi) with oxidized thin-film interference layer
Asphalt (Bituminous Concrete)
Composite material (bitumen binder with mineral aggregate)
Silver Nuggets (Natural or Cast)
Native Silver (Ag)
Painted River Pebble (likely Basalt or Greywacke)
Aphanitic Lithic Clast with Anthropogenic Pigment coating
Tiffany Stone
Bertrandite (with Fluorite, Opal, and Chalcedony), Be4Si2O7(OH)2
Concrete
Anthropogenic Sedimentary Rock (Hydrated Calcium Silicate)
Likely weathered metallic mineral or slag fragment
Uncertain; possibly limonite/goethite-coated iron mineral, or industrial iron slag
Green Quartz (Prasiolite or Aventurine)
Silicon Dioxide (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Likely weathered iron-rich rock or slag fragment
Uncertain; possibly limonite/goethite-rich material (FeO(OH)·nH₂O)
Titanium Aura Quartz (Bismuth-coated Druzy)
Silicon Dioxide (SiO2) with Titanium/Metal vapor coating
Bismuth Crystal
Bismuth (Bi)
Cullet Glass (Man-made Glass Slag)
Amorphous Silica (SiO2) with chemical additives
Chert (Arrowhead Fragment)
Microcrystalline Quartz (SiO2)
Possible tektite or volcanic glass specimen
Natural silica glass; composition commonly near SiO₂, but exact identification requires chemical testing
Green Slag Glass
Amorphous Silica / Glassy Blast Furnace Slag
Green sea glass (likely)
Anthropogenic glass, not a mineral; composition commonly soda–lime silicate glass
Silicon Carbide (Carborundum)
Silicon Carbide (SiC)
Concrete-like aggregate surface with embedded rock fragments
Anthropogenic concrete or exposed aggregate; not a natural rock specimen
Ferruginous Conglomerate (or Iron-Rich Concrete/Slag)
Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)
Painted River Rock
Artificially Coated Sedimentary Rock
Iron Slag
Iron Slag (Industrial Vitreous Material)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)