Precious Coral (Red Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
mineral
Category
Mineraloid (Synthetic)
Browse mineraloid (synthetic) specimens identified by the Rock Identifier community.
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Obsidian
Volcanic Glass (Amorphous Silica)
igneous
Blue opalite (often sold as synthetic opal)
Opalite glass; amorphous hydrated silica if natural opal (SiO₂·nH₂O)
gemstone
Opalite (a synthetic glass)
Silicon Dioxide (SiO2) with various additives; not a true mineral but a man-made gem simulant
Mineral Simulant (Synthetic Glass)
Diamond (or Diamond Simulant)
Carbon (C) if diamond, various if simulant
gemstone
Cubic Zirconia (Diamond Simulant)
Zirconium Dioxide (ZrO2)
gemstone
Cubic Zirconia
Zirconium Dioxide (ZrO2)
mineral
Cultured Marble (Synthetic)
Polymer-matrix composite (typically calcium carbonate in polyester resin)
Synthetic / Composite Material
Diamond (or synthetic simulant)
Cubic C (Carbon)
mineral
Hematite
Iron(III) oxide (Fe2O3)
mineral
Chrysocolla in Malachite
Cu2CO3(OH)2 (Malachite) / Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla)
mineral
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Mineral
Colorless faceted gemstone, likely cubic zirconia
Cubic zirconia (zirconium dioxide, ZrO₂); visual confirmation is unavailable
gemstone
Aquamarine in Onyx / Blue Topaz Pendant
Beryl (Be₃Al₂Si₆O₁₈) or Topaz (Al₂SiO₄(F,OH)₂)
gemstone
Diamond (Baguette cut)
Carbon (C)
gemstone
Ruby (Corundum)
Aluminum oxide (Al2O3) with Chromium traces
mineral
Diamond
Diamond (C)
gemstone
Blue Agate Geode (Dyed)
Cryptocrystalline Quartz (SiO2)
mineral
Ruby (varieties of Corundum)
Aluminum oxide (Al2O3) with Chromium traces
mineral
Emerald
Beryl, Be₃Al₂(SiO₃)₆, colored green mainly by chromium and/or vanadium
gemstone
Ruby
Corundum (Al2O3 with Chromium traces)
mineral
Acrylic or Resin (Synthetic Imitation)
Polymethyl Methacrylate (PMMA) or Polyepoxide
Synthetic/Man-made Polymer
Agate (Polished Sphere)
Silicon Dioxide (SiO2)
mineral
Cubic Zirconia (Faceted Gemstone)
Zirconium dioxide (ZrO2)
gemstone
Blue-beaded gemstone jewelry, likely lapis lazuli or dyed blue agate
Uncertain from the image; possible lazurite-bearing lapis lazuli (Na₃Ca(Si₃Al₃)O₁₂S) or blue chalcedony (SiO₂)
gemstone
Beach Pebble Quartzite / Chalcedony Pebble
Silicon Dioxide (SiO2)
metamorphic
Painted River Rock
Artificially Coated Sedimentary Rock
sedimentary
Strawberry Quartz
Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)
mineral
Zircon
Zirconium Silicate (ZrSiO₄)
mineral
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
igneous
Obsidian
Volcanic glass
igneous
Obsidian
Volcanic Glass (felsic composition)
igneous
Obsidian
Volcanic Glass (Silicon Dioxide with impurities)
igneous
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite (SiO2 + Fe2O3)
igneous
Obsidian
Obsidian (Amorphous volcanic glass, SiO2 with impurities)
igneous
Snowflake Obsidian
Volcanic glass containing Spherulites (SiO2)
igneous
Amber
Succinite (with a generalized formula of C10H16O)
mineral
Emerald
Beryl (Be₃Al₂(SiO₃)‑₆) with Chromium/Vanadium impurities
mineral
Obsidian
Obsidian (Volcanic Glass)
igneous
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Staurolite (Fairy Stone)
Staurolite (Fe2+2Al9Si4O23(OH))
metamorphic
Fluorite
Calcium Fluoride (CaF2)
mineral