Blue chalcedony (likely dyed or treated)
Microcrystalline quartz, SiO₂ (chalcedony)
Category
Browse man made composite specimens identified by the Rock Identifier community.
Blue chalcedony (likely dyed or treated)
Microcrystalline quartz, SiO₂ (chalcedony)
Blue Obsidian (Cullet Glass)
Silicon Dioxide (Amorphous Glass)
Tumbled milky chalcedony (likely common opalite-like quartz)
Chalcedony, microcrystalline SiO₂; possibly pale common opal, hydrated SiO₂·nH₂O
Colorless quartz crystal (likely quartz fragment)
Quartz, silicon dioxide (SiO₂)
Obsidian (likely black volcanic glass)
Obsidian; primarily amorphous volcanic silica glass, approximately SiO₂-rich rhyolitic composition
Carborundum
Silicon Carbide (SiC)
Opalite
Synthetic Opalised Glass
Carborundum (Silicon Carbide)
Silicon Carbide (SiC) / Moissanite (natural form)
Opalite-style pendant (likely synthetic glass, not natural opal)
Opalescent glass; commonly sold as “opalite” (not a recognized mineral species)
Cullet (Slag Glass)
Amorphous Silica (Industrial byproduct)
Likely clear quartz crystal or glass-like gemstone
Quartz, silicon dioxide (SiO₂); exact identification is uncertain from the strongly magenta-lit image
Polished obsidian
Volcanic glass; predominantly rhyolitic SiO₂
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
Agate and millefiori glass jewelry
Agate: microcrystalline quartz (SiO₂); millefiori element appears to be man-made glass
Ferruginous Conglomerate (or Iron-Rich Concrete/Slag)
Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)
Blue Goldstone
Synthetic Avanturine Glass (or Aventurine Glass)
Pink Cubic Zirconia (CZ)
Zirconium Dioxide (ZrO2)
Green glassy mineral fragment, possibly fluorite
Fluorite (calcium fluoride, CaF₂), tentative identification
Man-made Ceramic / Clay Figurine
Aluminosilicate Ceramic (Processed Clay)
Rainbow Hematite (Man-made/Treated)
Tumbled Hematite with Titanium/Anodized coating (Iron(III) oxide, Fe2O3)
Glass / Silicon Dioxide (Man-made)
SiO2 (Amorphous Silicon Dioxide)
Man-made Blank Ammunition (Brass)
CuZn (Cartridge Brass - roughly 70% Copper, 30% Zinc)
Blue sea glass or blue glassy mineral fragment
Uncertain; likely man-made soda-lime glass, not a natural mineral
Blue glassy fragment among beach gravel
Likely cobalt-blue man-made glass; not a natural mineral specimen
Opalite
Man-made synthetic glass with opalescent effects (SiO2 + metal oxides)
Slag Glass (Cullet)
Amorphous Silica (man-made), primarily SiO2 with trace metal oxides
Aventurine
Quartz containing inclusions of Fuchsite (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Ferro-silicate Slag
Industrial Vitrified Slag (High-silica amorphous glass)
Tumbled black stone, likely black obsidian
Obsidian; volcanic glass, typically rhyolitic composition (SiO₂-rich)
Man-made Glass (Tumbled/Shaped)
Amorphous Silicon Dioxide (SiO2) with metal oxide colorants
Man-made Slag (Industrial Byproduct)
Anthropogenic Glassy Residue
Man-made Crystal (Lead Glass)
Lead oxide-doped Silica Glass (approx. SiO2 + PbO)
Man-made Dyed Aura Quartz
Silicon Dioxide (SiO2) with metallic coating/dye
Purple glassy pebble, possibly slag glass
Unidentified; likely man-made glass rather than a natural mineral
Goldstone (brown goldstone)
Man-made aventurine glass, typically copper-bearing silica glass
Green sea glass (likely slag glass or bottle glass)
Man-made soda-lime silicate glass; not a naturally occurring mineral
Green Sea Glass
Amorphous Silica (man-made glass), SiO2 + additive metal oxides
Tumbled black obsidian (likely)
Volcanic glass; chiefly silica-rich rhyolitic glass (SiO₂)
Engineered Quartz Stone
Agglomerated Quartz (SiO2 + Polymer Resin)
Slag Glass (Leland Blue variant)
Anthropogenic Vitreous Silicate
Smelter Slag
Anthropogenic Silicate Slag
Libyan Desert Glass
Impact-melt silica glass (SiO2 + traces of Al, Fe, Ti)