Man Made Material (Jewelry, Metal Alloy)

Slag (Industrial Glassy Byproduct)

Anthropogenic silicate byproduct (Slag)

Tumbled black stone, likely black obsidian

Obsidian; volcanic glass, typically rhyolitic composition (SiO₂-rich)

Diamond

Diamond (C)

Green cabochon gemstone pendant

Indeterminate; likely dyed green turquoise, chrysoprase, or opaque beryl set with blue/clear accent stones

Blue aventurine or dyed blue quartzite pendant

Quartz (SiO₂), likely aventurine quartz/quartzite; exact identification requires testing

Bismuth Crystal

Bismuth (Bi)

Faceted colorless gemstone, likely cubic zirconia or diamond

Cubic zirconia (zirconium dioxide, ZrO₂) or diamond (carbon, C)

Amethyst chip or polished fragment

Quartz, purple variety (SiO₂), likely mounted or attached to metal

Chert or Jasper

Microcrystalline Quartz (SiO2)

Limpets Shell / Fossil Specimen

Patellogastropoda (Class)

Likely black cabochon gemstone pendant

Uncertain; possibly black star sapphire, black spinel, or obsidian

Likely quartz cabochon in a ring

Quartz (SiO₂), possibly clear or milky quartz; identification is uncertain from the photograph

Hematite Beads

Hematite (Fe2O3)

Slag (Industrial)

N/A (Anthropogenic Slag)

Unidentified metallic mineral or metal-like specimen

Indeterminate from image; possibly galena (PbS) or a metallic sulfide

Faceted citrine pendant

Citrine, gem-quality quartz (SiO₂), likely heat-treated amethyst

Amethyst cabochon jewelry

Amethyst, purple variety of quartz (SiO₂)

Faceted blue gemstone, likely blue topaz or synthetic spinel

Topaz (Al₂SiO₄(F,OH)₂) or synthetic spinel (MgAl₂O₄); image insufficient for certainty

Faceted gemstone ring, likely smoky quartz or garnet in a metal setting

Not determinable from the photograph; possible quartz (SiO₂) or garnet-group silicate

Chert (Arrowhead/Artifact Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Slag (Industrial Glassy Byproduct)

Ferro-silicate Slag

Star sapphire ring

Corundum (Al₂O₃), likely asteriated sapphire

Diamond jewelry pendant or cluster

Diamond, crystalline carbon (C), likely mounted in metal

Diamond

Carbon (C)

Ruby in Matrix

Corundum (Al2O3)

Red cabochon gemstone, likely carnelian or red agate

Cryptocrystalline quartz (chalcedony), SiO₂

Quartzite Pebble

Quartzite (SiO2)

Olivine

(Mg,Fe)2SiO4

Yellow faceted gemstone earrings, likely citrine or yellow beryl

Citrine: quartz, SiO₂; possible yellow beryl: Be₃Al₂Si₆O₁₈

Blue glassy fragment among beach gravel

Likely cobalt-blue man-made glass; not a natural mineral specimen

Tumbled fossil shark tooth pendant

Likely fossilized shark tooth, possibly Otodus or Carcharhinus; exact species cannot be confirmed from the image

Chert (likely flint)

Microcrystalline quartz, SiO₂

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Polished yellow jasper cabochon

Jasper, microcrystalline quartz (SiO₂) with iron-oxide and clay inclusions

Weathered concrete or cementitious slab (not natural rock)

Artificial calcium-silicate cement composite; likely Portland cement concrete

Gemstone Ring

N/A - Set piece of jewelry, likely Amethyst or Garnet with Diamond or CZ

Turquoise cabochon pendant

Turquoise, hydrated copper aluminum phosphate — CuAl₆(PO₄)₄(OH)₈·4H₂O

Asphalt Pavement (with aggregate)

Asphalt concrete

Peridot (Olivine)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Polished serpentine pendulum

Serpentine-group minerals, chiefly antigorite/lizardite; approximate formula Mg₃Si₂O₅(OH)₄

Polished dark chalcedony or agate cabochon

Cryptocrystalline quartz, SiO₂; likely brown-red chalcedony/agate

Diamond (Cut Gemstone)

Natural Carbon (C)