Chalk
Calcium Carbonate (CaCO3)
sedimentary
Category
Anthropogenic Sedimentary (Man Made)
Browse anthropogenic sedimentary (man made) specimens identified by the Rock Identifier community.
Learn about Anthropogenic Sedimentary (Man Made) in the encyclopedia
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Grooved Maun Ball (Maul/Hammerstone-like Concretion)
Calcareous/Ferruginous Concretion in Sandstone Matrix
sedimentary
Blue Chalcedony Cube
Silicon Dioxide (SiO2)
mineral
Jewelry Chain with Blue and Clear Gemstones (Likely Cubic Zirconia)
Cubic Zirconia (ZrO₂), Silver or White Gold/Platinum Alloy
Mineral (synthetic) and Metal (precious/base)
Man-made Synthetic Material (Not a rock or mineral)
Polyester (Polyethylene terephthalate) / Faux Fur
Synthetic / Textile
Blue Sapphire (Synthetic or Man-made Glass Imitation)
Corundum (Al2O3) if natural; Lead-glass or Spinal if synthetic
mineral
Man-made Synthetic Material (Costume Faux Fur)
Synthetic Polymer (Polyester/Acrylic)
not a rock
Mystic Topaz
Aluminum silicate fluoride hydroxide with titanium coating (Al2SiO4(F,OH)2)
mineral
Cupronickel (on a 1981 Mexico 20 Pesos coin)
Copper-Nickel Alloy (Cu75Ni25)
mineral
Sandstone Concretion
Sedimentary concretion
Sedimentary
Turquoise
Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O
mineral
Possible tektite or volcanic glass specimen
Natural silica glass; composition commonly near SiO₂, but exact identification requires chemical testing
mineral
Iron Slag
Anthropogenic Iron oxide/Silicate composite
Mineral-like byproduct (Technogenic)
Iron Slag
Anthropogenic Vitreous Silicate (Byproduct of Smelting)
Mineral-like byproduct
Slag (Industrial By-product)
Anthropogenic Vitreous Silica/Iron Silicate
mineral
Grey Chalcedony
Silicon Dioxide (SiO2)
mineral
Basalt
Basalt (Mafic volcanic rock)
igneous
Slag (Industrial Byproduct)
Ferro-silicate glass (Slag)
Anthropogenic (Man-made industrial deposit)
Sea Glass (Frosted Glass)
Amorphous Silica (SiO2) with various additives
Man-made material (Anthropogenic 'mineraloid')
Iron Slag
Ferrous slag (primarily silicates and oxides of calcium, iron, and magnesium)
Anthropogenic (Man-made industrial byproduct)
Slag
Ferrous Slag (Siliceous industrial waste)
Anthropogenic (Man-made industrial byproduct)
Sea Glass (Uranium/Vaseline Glass variant)
Silicon Dioxide (SiO2) with trace Uranium Oxide (U3O8)
man-made silicate (anthropogenic glass)
Fossil Shark Tooth
Lamniform (Mackerel Shark) fossil tooth, likely Otodus or Cretalamna
fossil
Ferrous Slag (Iron Smelting By-product)
Fused Siliceous Slag
Anthropogenic Material (Man-made Rock)
Sea Glass (Kelly Green)
Amorphous Silica (Silicon Dioxide with Iron/Chromium additives)
Anthropogenic specimen (Man-made material)
Obsidian Arrowhead
Obsidian (Volcanic Glass)
igneous
Slag
Anthropogenic Vitrophyre (Iron or Smelting Slag)
Mineral-like byproduct
Sea Glass
Amorphous Silica (Anthropogenic glass) - SiO2
mineral
Chert
Chert (Microcrystalline Quartz)
sedimentary
Tiger Shark Fossil Tooth
Galeocerdo cuvier (fossilized)
sedimentary
Sandstone
Clastic Sedimentary Rock
sedimentary
Turquoise (likely stabilized or simulated Howlite)
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
mineral
Chert (Flint/Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Fossil Sea Urchin (Echinoid)
Echinoidea fossil (often replaced by silica or calcite)
fossil
Blue chalcedony cabochon (probable)
Chalcedony, a cryptocrystalline variety of quartz; silicon dioxide, SiO₂
gemstone
Coquina
Bioclastic Limestone
sedimentary
Coquina
Bioclastic Limestone
sedimentary
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Possible tektite or iron-rich slag-like natural specimen
Uncertain; possibly natural glass (tektite) or magnetite-rich rock
mineral
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone
Arenite
sedimentary