Opalite
Synthetic opalescent glass
Category
Browse anthropogenic (man made material processed by nature) specimens identified by the Rock Identifier community.
Opalite
Synthetic opalescent glass
Chert Arrowhead (Projectile Point)
Chert (Cryptocrystalline Quartz, SiO2)
Cherry Quartz
SiO2 (Silicon Dioxide with iron-rich inclusions/dye)
Flint
Silicon Dioxide (SiO2) - Chert variety
Libyan Desert Glass
Libyan Desert Glass (SiO2 with trace elements)
Weathered iron-rich concretion or ironstone nodule
Goethite–hematite limonite concretion (FeO(OH), Fe₂O₃, and hydrated iron oxides)
Hematite Beads
Hematite (Fe2O3)
Nephrite Jade
Nephrite
Opalite (Man-made Glass)
Synthetic Silicon Dioxide Glass (SiO2 + metal oxides)
Aventurine Quartz
Silicon Dioxide (SiO2) with Fuchsite inclusions
Milky quartz (likely rough quartz crystal)
Quartz, silicon dioxide (SiO₂)
White pebbles (rock material not identifiable from the image)
Undetermined; the smooth, pale pieces could be quartz, quartzite, or another light-colored rock
Cupronickel (on a 1981 Mexico 20 Pesos coin)
Copper-Nickel Alloy (Cu75Ni25)
Dyed Agate / Painted Stone
Silicon Dioxide (SiO2) with artificial pigment
Opalite
Synthetic Fluorescent Glass (SiO2 + impurities)
Red Coral (Dyed or Reconstituted)
Corallium rubrum (if natural) or Calcite/Aragonite with dye
Likely blue glass or synthetic gemstone jewelry
Uncertain; possibly synthetic spinel, cubic zirconia, or blue glass
Vesicular basalt (probable iron-rich volcanic rock)
Basalt; chiefly plagioclase, clinopyroxene, olivine, and Fe-Ti oxides
Polished milky quartz (likely quartz worry stone or wand)
Quartz, silicon dioxide (SiO₂)
White quartz pebble
Quartz (SiO₂), likely milky quartz
Beaded mineral/crystal jewelry (likely turquoise and coral accents)
Variable; blue beads may be turquoise (CuAl6(PO4)4(OH)8·4H2O), with possible dyed howlite, glass, or composite materials
Blue glassy mineral specimen, possibly dyed or synthetic
Uncertain; possible blue fluorite (CaF₂), dyed chalcedony, or man-made glass
Opalite
Synthetic Opalised Glass
Road-surface aggregate (crushed stone)
Unidentifiable mixed lithic aggregate; likely basaltic/andesitic fragments with feldspar, quartz, and weathered rock
Sandstone Concretion
Septarian or Carbonate-cemented Sandstone Concretion
Tumbled quartz pebble
Quartz, silicon dioxide (SiO₂), likely milky quartz
Dalmatian jasper
Porphyritic microcrystalline quartz-rich rock, commonly sold as Dalmatian jasper; spots are chiefly arfvedsonite/amphibole minerals, sometimes altered feldspar
Iron Slag
Anthropogenic Vitreous Silicate (Byproduct of Smelting)
Green glass-like mineral specimen, likely fluorite
Fluorite (calcium fluoride, CaF₂), if natural; appearance may also indicate colored glass
Jasper with Iron Staining
Silicon Dioxide (SiO2) with impurities
Opalite (Man-made Glass)
Synthetic Opalised Glass
Slag
Metallurgical Slag
Blue Goldstone
Synthetic Avanturine Glass (or Aventurine Glass)
Moldavite
Tektite (Impact Glass), ~80% SiO2 + Al2O3
Tumbled clear quartz (rock crystal)
Quartz, silicon dioxide (SiO₂)
Blue goldstone
Man-made aventurine glass containing metallic copper particles; not a natural mineral
Polished labradorite pendant
Labradorite, a calcium-rich plagioclase feldspar (approximately NaAlSi₃O₈–CaAl₂Si₂O₈)
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
Man-made earbud charging case (Not a rock or mineral)
Acrylonitrile Butadiene Styrene (ABS) Plastic with electronic components
Leland Blue Stone
Anthropogenic Iron Smelting Slag
Black tumbled stone, possibly obsidian
Obsidian (volcanic glass; predominantly SiO₂), identification uncertain from image
Cullet Glass (Man-made Glass Slag)
Amorphous Silica (SiO2) with chemical additives