Blue Sapphire (Synthetic or Man-made Glass Imitation)
Corundum (Al2O3) if natural; Lead-glass or Spinal if synthetic
Category
Browse antropogenic rock (man made) specimens identified by the Rock Identifier community.
Blue Sapphire (Synthetic or Man-made Glass Imitation)
Corundum (Al2O3) if natural; Lead-glass or Spinal if synthetic
Terracotta (Man-made ceramic brick fragment)
Baked clay / High-iron ceramic (Silicate-based ceramic)
Desert Rose (Gypsum Rose)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Exposed aggregate concrete (stone-chip surface)
Portland-cement concrete containing natural aggregate; not a natural rock
Chert
Microcrystalline Quartz (SiO2)
Ferrous Slag (Iron Smelting By-product)
Fused Siliceous Slag
Chert (Flint)
Silicon dioxide (SiO2)
Sandstone
Arenite
Granite
Granite (a plutonic rock)
Quartz Pebble (Beach Chalcedony)
Silicon Dioxide (SiO2)
Siltstone Pebble
Siltstone (composed of microscopic quartz and clay minerals)
Chert Arrowhead
Cryptocrystalline Quartz (SiO2)
Granodiorite
Intrusive Igneous Rock
Jewelry Chain with Blue and Clear Gemstones (Likely Cubic Zirconia)
Cubic Zirconia (ZrO₂), Silver or White Gold/Platinum Alloy
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone
Arenite
Chert (White Chert/Flint)
Microcrystalline Quartz (SiO2)
Asphalt Chunk (with aggregate)
Bituminous concrete / Anthropogenic conglomerate
Vesicular Basalt (or Scoria)
Vesicular Basalt
Sandstone
Arenite (primarily SiO2)
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
Sandstone (Quartzose)
Arenite (composed primarily of SiO2)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Greenstone
Metabasalt / Metavolcanic rock
Sandstone
Arenite (composed primarily of SiO2)
Belemnoit (Fossil)
Belemnoidea (Order), Rostrum / Guard
Slate
Metamorphic Pelitic Rock
Slate
Metamorphic Pelitic Rock
Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3 inclusions)
Fossilized Coral (Coquina/Limestone)
Cnidaria Anthozoa (Fossilized)
Clay Brick
Ceramic structural unit (Al2O3·2SiO2·2H2O as precursor)
Sandstone
Arenite (mostly SiO2)
Granodiorite
Phaneritic Plutonic Intermediate-Felsic Rock
Chert (Flint / Quartz Nodule)
Microcrystalline Quartz (SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Sandstone (Water-worn Cobble)
Arenite (SiO2 with CaCO3 or Fe2O3 cement)
Asphalt (Bituminous Concrete)
Bituminous Concrete / Pavement
Chert
Silicon dioxide (SiO2)
Sandstone (with potential Arkose/Lithic characteristics)
Arenite (Sedimentary rock composed of sand-sized grains)
Eroded Brick or Pumice-like Scoria
Vesicular Basalt / Scoria (Anthropogenic variant: Eroded Firebrick)
Chert (Flint)
Silicon Dioxide (SiO2)
Fossil Coral
Scleractinia (Stony Coral) fossil