Mineraloid (Human Made Geological Specimen)

Fordite

Anthropogenic paint-rock

Not a geological specimen

N/A (man-made object)

Weathered concrete or cementitious slab (not natural rock)

Artificial calcium-silicate cement composite; likely Portland cement concrete

Synthetic Convention Badge (Plastic/PVC)

Polyvinyl Chloride (PVC) / Polycarbonate

Cullet Glass (Slag)

Amorphous Silicon Dioxide (Man-made)

Cullet Glass (Slag Glass)

Amorphous Silicon Dioxide (Industrial Byproduct)

Obsidian arrowhead

Volcanic glass; predominantly SiO₂, with minor feldspar, pyroxene, and iron oxides

Unidentified gray metallic object

Not determinable from the image; likely a metal screw or manufactured fastener rather than geological material

Polished black stone egg, probably black obsidian

Obsidian, a natural volcanic glass; composition primarily silica-rich glass (approximately SiO₂), with variable iron and other trace elements

Unidentified gray stone/concrete-like fragment

Indeterminate; likely a fine-grained carbonate or cementitious geological fragment

Opalite (Synthetic Moonstone/Opal)

Synthetic Silica Glass

Glass

Amorphous Silicon Dioxide (SiO2)

Exposed aggregate concrete (stone-chip surface)

Portland-cement concrete containing natural aggregate; not a natural rock

Aura Quartz (Titanium/Rainbow Quartz)

SiO2 (Silicon Dioxide) with metallic coating

Concrete or asphalt-like aggregate surface with a dark fragment

Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock

Gemstone ring (stones not reliably identifiable from the image)

Likely faceted yellow stones and clear stones set in a metal band; species and treatments are indeterminate visually

Green iridescent glass cabochon or synthetic gemstone

Likely synthetic glass; possibly coated synthetic quartz or lab-created green gemstone

Dark gray rounded stone, possibly basalt or slag

Uncertain; likely fine-grained basalt (plagioclase–pyroxene) or iron-rich industrial slag

Small metallic-looking mineral/rock fragment

Indeterminate from image; possibly galena, hematite, or metallic slag

Green sea glass or tumbled green quartz (uncertain)

Likely quartz (SiO₂) if natural; alternatively man-made soda-lime glass

Small dark rock fragment

Uncertain; possibly weathered basalt or slag

Likely obsidian (possibly tektite or slag glass)

Volcanic glass; primarily SiO₂, noncrystalline

Likely iron-rich rock or weathered metallic mineral fragment

Uncertain; possibly limonite/goethite or iron-bearing slag

Limonite (Iron Stone/Ocher)

Limonite (FeO(OH)·nH2O)

Conglomeratic concrete or asphalt aggregate surface with dark bituminous chunks

Polymictic gravel aggregate; dark pieces likely bitumen/asphalt, not a natural rock

Limonite or Ironstone Nodule

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)

Concrete / Anthropogenic Conglomerate

Man-made composite material (Portland cement, aggregate, and water)

Cullet Glass (Slag Glass)

Amorphous Silicon Dioxide (SiO2) with metallic oxide impurities

Green cabochon gemstone, likely aventurine or dyed chalcedony

Indeterminate from image; possible quartz variety (SiO₂), including aventurine quartz or chalcedony

Kidney Stone

Calcium oxalate, uric acid, struvite, or cystine

Yellow faceted gemstone, likely citrine or synthetic glass

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

Pet Rock (Man-made Quartzite or Granite Cobble)

Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica

White cabochon gemstone, likely milky chalcedony or opalite

Chalcedony: microcrystalline quartz, SiO₂; appearance may also indicate synthetic opalite glass

Polished black stone carving, likely soapstone/steatite

Steatite (massive talc), Mg₃Si₄O₁₀(OH)₂; exact material cannot be confirmed from the image

Likely tumbled epidote-bearing rock or green jasper

Epidote-group silicate, possibly in a jasper or serpentinite matrix

Tumbled blue stone, likely blue calcite or dyed stone

Probably calcite (CaCO₃); exact identification is uncertain from the blurred image

Fired Clay Brick (Anthropic Rock substitute)

Anthropogenic polycrystalline ceramic (predominantly Mullite and Quartz: Al6Si2O13 + SiO2)

Stone bead bracelet

Unidentified polished natural-stone beads; possibly wood-grain jasper, agate, or serpentine

Raw quartz crystal pendant

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

Carved labradorite fish

Labradorite, calcium-rich plagioclase feldspar (approximately (Ca,Na)(Al,Si)₄O₈)

Dark green cabochon gemstone ring

Unknown; possibly green onyx (cryptocrystalline quartz, SiO₂) or another green gem

Blue glass-like bead or gemstone keychain ornament

Indeterminate; likely cobalt-blue glass or synthetic blue spinel, not identifiable as a natural mineral from the image