Man-made Synthetic Material (Plastic/Composite)
Acrylonitrile Butadiene Styrene (ABS) or High-Impact Polystyrene (HIPS)
Category
Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.
Man-made Synthetic Material (Plastic/Composite)
Acrylonitrile Butadiene Styrene (ABS) or High-Impact Polystyrene (HIPS)
Chert (Flint)
Chert (SiO2)
Coquina and Oyster Fossil Rock
Coquina limestone (Calcium Carbonate, CaCO3) containing fossilized Crassostrea / bivalve shells
Gray Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (often called Flint)
Chert (SiO2)
Chert (with nodule)
Microcrystalline Quartz (SiO2)
Man-made Jewelry Charm (Enameled Metal)
Not a natural mineral; composed of base metal alloy (likely zinc or brass) and epoxy resin/enamel.
Turquoise (with Hematite)
CuAl6(PO4)4(OH)8·4H2O
Brown Chert
Microcrystalline Quartz (SiO2)
Flint Arrowhead
Cryptocrystalline quartz (Chert/Flint, SiO2)
Banded Chert Arrowhead (Projectile Point)
Microcrystalline Quartz (SiO2)
Opalite
Synthetic Glass, SiO2 base with metallic inclusions
Obsidian
Amorphous volcanic glass (primarily SiO2)
Blue Opal Inlay (Simulated/Lab-created)
Hydrated Amorphous Silica (SiO2·nH2O) with polymer resin
Common Opal (Potch)
Hydrated Silica (SiO2·nH2O)
Agate (Chalcedony)
Silicon Dioxide (SiO2)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Kidney Stone
Calcium Oxalate (CaC2O4), Uric Acid, or Struvite
Chert (Jasper and Chalcedony)
Silicon Dioxide (SiO2)
Obsidian
Obsidian (Volcanic Glass)
Chert / Flint Arrowhead
Microcrystalline Quartz (SiO2)
Flint
Sedimentary cryptocrystalline quartz (SiO2)
Obsidian
Obsidian (Volcanic Glass; SiO2 content > 70%)
Limonite (with Pyrite)
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (often called Flint when dark or worked)
Cryptocrystalline silica (SiO2)
Pyrite
Iron Sulfide (FeS2)
Chert (Green Chert or Jasper)
Microcrystalline Quartz (SiO2)
Man-made Slag (Industrial Byproduct)
Anthropogenic Glassy Residue
Weathered iron-rich concretion or ironstone nodule
Goethite–hematite limonite concretion (FeO(OH), Fe₂O₃, and hydrated iron oxides)
Amber
Succinite (fossilized resin); C10H16O
Natural White Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin - CaCO3
Chert (Flint)
Microcrystalline Quartz (SiO2)
Obsidian
Volcanic Glass (SiO2)
Land Snail Shell
Gastropoda (Calcium Carbonate, CaCO3)
Chert (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
Flint (or Chert)
Cryptocrystalline Quartz (SiO2)
Inukshuk Rock Sculpture (composed of Granite, Slate, and Amethyst)
Silicon Dioxide (Amethyst portion, SiO2) with mixed silicate rock assemblage
Blue Agate (Dyed Chalcedony)
Silicon Dioxide (SiO2)
Gold Sheen Obsidian
Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)
Polished black obsidian pyramid/block
Obsidian — natural volcanic glass, chiefly rhyolitic silica (approximately 70–75% SiO₂)