Man Made Glass

Chert (Flint)

Microcrystalline Quartz (SiO2)

Sea Glass (Frosted Glass)

Amorphous Silica (SiO2) with various metal oxide impurities

Chert

Microcrystalline quartz (SiO2)

Smoky Quartz Cluster

Smoky Quartz (Silicon Dioxide - SiO2)

Smoky Quartz

Smoky Quartz (Silicon Dioxide - SiO2)

Amethyst (with Pyrite and other minerals)

Silicon Dioxide (SiO2)

Chert Pebble/Nodule

Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)

Amethyst

Silicon Dioxide (SiO2) with Fe3+ impurities

Chert (often called Flint)

Microcrystalline Quartz (SiO2)

Chert Pebble

Chert (Microcrystalline Quartz, SiO2)

Beaded mineral/crystal jewelry (likely turquoise and coral accents)

Variable; blue beads may be turquoise (CuAl6(PO4)4(OH)8·4H2O), with possible dyed howlite, glass, or composite materials

Smoky Quartz

Smoky Quartz (Silicon Dioxide, SiO2)

Cullet Glass (Industrial Slag Glass)

Amorphous Silica (SiO2) with metallic oxide impurities

Iron Slag

Ferrous slag (primarily silicates and oxides of calcium, iron, and magnesium)

Beaded blue-and-green gemstone jewelry

Likely dyed or treated chalcedony/agate and green aventurine or glass-like stone; exact identification requires testing

Pearl-and-gemstone insect brooch

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

Blue gemstone bead bracelet, likely lapis lazuli or dyed stone

Uncertain from image; possible lazurite-bearing lapis lazuli (Na₃Ca(Si₃Al₃)O₁₂S) or dyed quartz/glass imitation

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Sandstone

Sandstone (Quartz-rich Arenite / SiO2)

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Jasper

Silicon Dioxide (SiO2)

Sea Glass (Teal/Turquoise)

Amorphous Silica (SiO2) with trace metal oxides

River Pebbles (Chert and Quartzite)

Sedimentary Clastic Rock (Silica-rich)

Chert (and associated river cobbles)

Silicon dioxide (SiO2)

Chert (and/or Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Chert

Microcrystalline Quartz (SiO2)

Chert (Flint)

Chert (Microcrystalline or cryptocrystalline Quartz - SiO2)

Chert (Flint)

Chert (Microcrystalline Quartz, SiO2)

Tektite

Impactite (Natural Silicate Glass)

Quartz

Silicon dioxide (SiO₂)

Beaded gemstone jewelry, likely carnelian and green aventurine

Carnelian: orange chalcedony (microcrystalline SiO₂); green aventurine: quartz with fuchsite or other inclusions (SiO₂)

Pink Granite

Phaneritic Felsic Intrusive Igneous Rock

Chert (Field-collected Arrowhead-shaped Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone (Red/Brown Variety)

Arenite (composed primarily of SiO2 with Fe2O3 iron oxide inclusions)

Sandstone (likely Fossiliferous)

Arenite / Fossiliferous Sandstone (SiO2 composition)

Tumbled yellow jasper or chalcedony

Microcrystalline quartz, SiO₂; likely iron-oxide-bearing jasper/chalcedony

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Amethyst Cluster

Silicon Dioxide with Iron impurities (SiO2)

Chert (and Flint)

Silicon Dioxide (SiO2)

Polished black obsidian

Volcanic glass; primarily rhyolitic SiO₂, with minor iron, magnesium, and other trace elements

Diamond (or Diamond Simulant)

Carbon (C)