Man Made (Synthetic Rock)

Synthetic Convention Badge (Plastic/PVC)

Polyvinyl Chloride (PVC) / Polycarbonate

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)

Diamond / Clear Quartz / Glass paste

Carbon (Diamond) / Silicon Dioxide (Quartz)

Diamond (or Cubic Zirconia)

Carbon (C) or Zirconium Dioxide (ZrO2)

Strawberry Quartz

Silicon Dioxide (SiO2) with Hematite/Goethite inclusions

Quartz (likely milky quartz or quartz glass-like fragment)

Quartz, silicon dioxide (SiO₂)

Black tumbled stone, possibly obsidian

Obsidian (volcanic glass; predominantly SiO₂), identification uncertain from image

Rounded graywacke or sandstone cobble

Lithified clastic sandstone; likely quartz–feldspar–lithic grain aggregate in a silica or calcite matrix

Silicon Carbide (Carborundum)

Silicon Carbide, SiC

Pearls (likely freshwater cultured pearls)

Pearl: nacre, primarily aragonite (CaCO₃) with conchiolin

Tumbled opalite (likely man-made glass)

Opalite, a trade name for opalescent glass; not natural opal

Faceted Gemstone

Unknown transparent mineral, possibly Diamond (C), Cubic Zirconia (ZrO2), Quartz (SiO2), or Glass

Yellow faceted gemstone, likely citrine or synthetic glass

Citrine (quartz, SiO₂) is the leading natural possibility; visual identification is uncertain from the photograph

Painted River Rock

Painted Quartzite or Smooth Siltstone

Man-made Metal Pin (Non-geological)

Antimony-Lead Alloy or Zinc/Brass Base with Electroplating

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)

Bismuth crystal

Bismuth (Bi), synthetic laboratory-grown crystal

Aura Quartz

Titanium-coated Silicon Dioxide (SiO2)

Concrete with Aggregate

Composite construction material; primary matrix is Calcium Silicate Hydrate (C-S-H)

Ferrochrome Slag

Anthropogenic slag (Fe-Cr alloy waste)

Painted Rock

Weathered Sedimentary Rock (Painted)

Fluorite (Polished Point/Tower)

Calcium Fluoride (CaF2)

Blue Glass or Slag Glass

Amorphous Silica (Anthropogenic Glass)

Blue-dyed tumbled quartz or glass imitation

Quartz (SiO₂), appearance possibly enhanced with blue dye; identity uncertain from image

Faceted Clear Quartz or Diamond Simulant

Silicon Dioxide (SiO2) if Quartz or Cubic Zirconia (ZrO2) if Synthetic

Blue Goldstone

Man-made glass with suspended copper, cobalt, or manganese particles

Blue opalite (often sold as synthetic opal)

Opalite glass; amorphous hydrated silica if natural opal (SiO₂·nH₂O)

Quartz crystal (likely clear quartz)

Quartz, silicon dioxide (SiO₂)

Polished black stone, likely black obsidian

Obsidian (volcanic glass), chiefly silica-rich rhyolitic composition

Pink Tumbled Quartz (Dyed)

Silicon Dioxide (SiO2)

Dyed Crackle Quartz (Green)

Quenching-treated Quartz (Silicon Dioxide, SiO2)

Pyrite Concretion (Grapestone)

Iron Sulfide (FeS2) Concretion

Black glassy fragment, likely obsidian or industrial glass

Volcanic glass (obsidian), chiefly amorphous SiO₂; identification uncertain from image

Tumbled gray stone, likely quartz-rich pebble

Probable microcrystalline quartz/chalcedony (SiO₂), possibly gray jasper or quartzite

Sea Glass

Amorphous silicon dioxide (SiO2) - Man-made glass tumbled by nature

Sea Glass (White/Clear)

Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO

Milky quartz (likely quartz crystal fragment)

Quartz, silicon dioxide (SiO₂)

Slag Glass

SiO2 (Silicon Dioxide) with impurities

The user-provided image does not contain a rock or mineral specimen

Green glass cabochon or tumbled stone

Indeterminate; likely man-made glass, possibly aventurine glass rather than a natural mineral

Terrazzo (with Marble and Granite fragments)

Cementitious or resinous composite containing Calcium Carbonate (CaCO3) and Silicates

Black Obsidian

Amorphous volcanic glass (SiO2 + impurities)