Synthetic (Man Made Material Mimicking Natural Stone)

Raw quartz crystal

Quartz (silicon dioxide, SiO₂), likely milky or included quartz

Ferruginous Conglomerate (or Iron-Rich Concrete/Slag)

Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)

Transit Token (RTD Denver)

Nickel-plated brass or bronze alloy (Cu-Sn-Zn-Ni)

Tumbled aqua glassy mineral specimen, likely chrysocolla or turquoise imitation

Uncertain from image; possible chrysocolla (hydrated copper aluminosilicate, variable composition) or dyed/man-made glass

Green glassy cabochon, likely dyed or synthetic material

Uncertain; possibly green obsidian, chrysoprase, or synthetic glass

Tumbled chert or jasper pebble

Microcrystalline quartz (SiO₂), likely chert/jasper

Pearl-and-gemstone insect brooch

Pearl: nacre (aragonite, CaCO₃); colored stones are likely synthetic or natural corundum/spinel/glass, not determinable from the image

Ferro-silicate Slag

Industrial Vitrified Slag (High-silica amorphous glass)

K2 Stone (or K2 Jasper)

Azurite-in-Granite (Potassium Feldspar, Quartz, Plagioclase, Muscovite, and Azurite)

Polished ruby cabochon (likely synthetic or treated)

Corundum, aluminum oxide (Al₂O₃), colored red by chromium

Engraved purple stone cabochon, possibly amethyst

Unconfirmed; if amethyst, quartz (SiO₂)

Polished blue-green glassy slag or coated mineral fragment

Most likely man-made colored glass/slag; exact composition cannot be determined visually

Dyed Agate / Painted Stone

Silicon Dioxide (SiO2) with artificial pigment

Opal cabochon or opal-like decorative specimen

Hydrated amorphous silica, SiO₂·nH₂O; likely synthetic or assembled opal material

Diamond (or Diamond Simulant)

Carbon (C) if diamond, various if simulant

Red gemstone ring, likely ruby or synthetic ruby

Corundum (Al₂O₃), chromium-colored; natural versus synthetic cannot be determined from the photo

Blue gemstone cross pendant

Likely faceted blue topaz (Al₂SiO₄(F,OH)₂); identification is uncertain from the image

Mother of Pearl (Nacre)

Aragonite (CaCO3) with Organic Matrix

Ruby ring (likely synthetic ruby)

Corundum, Al₂O₃; red color from chromium. The image alone cannot establish whether the stone is natural or lab-grown.

Blue slag glass / industrial glass fragment

Artificial silicate glass, composition variable; likely copper- or cobalt-colored furnace slag

Engineered Quartz (Quartzite look-alike)

Silicon Dioxide (SiO2) composite

Faceted citrine-colored gemstone

Likely citrine (quartz, SiO₂); possibly yellow glass or synthetic gem

Faceted pale-green gemstone, likely prasiolite or green quartz

Quartz (SiO₂), likely prasiolite; identification is uncertain from the photograph

Diamond

Carbon (C)

Blue stone cabochon, likely lapis lazuli or dyed stone

Lapis lazuli: lazurite-rich rock, chiefly (Na,Ca)₈(AlSiO₄)₆(S,SO)₂; exact identification is uncertain from the image

Purple diamond (rough gem-quality diamond)

Diamond, crystalline carbon (C)

Gemstone butterfly brooch/pendant

Likely faceted pink tourmaline or synthetic spinel in gilt metal; exact identification requires testing

Red gemstone ring, likely synthetic ruby or red glass; exact stone cannot be confirmed from the image

Ruby (corundum, Al₂O₃) if natural; the setting appears to be silver-tone metal

Hematite cameo or hematine imitation

Hematite (Fe₂O₃); possibly synthetic hematine or black glass

Synthetic Sapphire and Ion-X Glass

Single-crystal Alumina (Al2O3) and Ion-strengthened Aluminosilicate Glass

Clear quartz fragment (rock crystal)

Quartz, silicon dioxide (SiO₂)

Blue glass-like gemstone, likely synthetic spinel or glass

Uncertain; possibilities include synthetic cobalt-blue spinel (MgAl₂O₄) or cobalt-colored glass

Small faceted gemstone, likely diamond

Diamond (crystalline carbon, C)

Asphalt aggregate (crushed stone in bitumen)

Artificial composite; predominantly crushed granite, basalt, limestone, and/or recycled aggregate bound by bitumen

Vesicular basalt (weathered scoria)

Scoriaceous basalt; chiefly plagioclase, clinopyroxene, olivine, and iron-titanium oxides

Milky quartz (likely)

Quartz, silicon dioxide (SiO₂)

Chert

Microcrystalline Quartz (SiO2)

Iron Slag (Industrial Byproduct)

Anthropogenic Vitrification Product/Ferrous Slag

Slag (Industrial Glass/Glassy Rock)

Anthropogenic Vitreous Material

Emerald

Beryl, Be₃Al₂(SiO₃)₆, colored green mainly by chromium and/or vanadium

Amethyst stud earrings

Amethyst, purple quartz (SiO₂)

Opal-like cabochon ring stone

Likely common opal (hydrated amorphous silica, SiO₂·nH₂O); exact material uncertain from the photograph