Man Made Material (Anthropogenic 'Mineraloid')

Green iridescent glass cabochon or synthetic gemstone

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

Pumice or vesicular volcanic tuff

Pumice: highly vesicular volcanic glass, chiefly rhyolitic to dacitic; possible tuff: lithified ash and pumice fragments

Sandstone (Quartzose)

Sandstone (SiO2 dominated)

Sandstone

Arenite (primarily SiO2)

Sandstone (Ferruginous)

Arenite with Iron Oxide cement (primarily SiO2 with Fe2O3)

Chert (Flint)

Chert (Cryptocrystalline Silica, SiO2)

Chert (and associated river cobbles)

Silicon dioxide (SiO2)

Chert (and/or Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (often called Flint)

Chert (SiO2)

Blue glass-like tumbled specimen

Most likely cobalt-blue slag glass or manufactured glass; not confidently identifiable as a natural mineral from the image

Tektite (likely Australite)

Tektite (no specific chemical formula as it's a natural glass of variable composition, mostly SiO2, Al2O3, FeO, MgO, CaO, K2O, Na2O, TiO2)

Green Slag Glass

Cullet (Amorphous Silicon Dioxide with impurities)

Sandstone

Sedimentary Rock (Quartz arenite)

Amber cabochon pendant

Amber (fossilized plant resin), chiefly polymerized diterpenoid resin

Black-and-white agate or onyx bead necklace

Variegated chalcedony (microcrystalline SiO₂), possibly black-and-white banded agate; some black beads may be dyed chalcedony or hematite

Bituminous Coal (with Anthracite or Vitrinite inclusion)

Organic-rich Sedimentary Rock (Carboniferous classification)

Chert (often called Flint or Agate nodule)

Cryptocrystalline Quartz (SiO2)

Chipped Glass/Plastic Fragment

Silicon dioxide (SiO2) for glass (amorphous) or various polymer compounds for plastic

Blue faceted gemstone ring, likely synthetic sapphire or blue topaz

Uncertain from image; possible corundum (Al₂O₃) or topaz (Al₂SiO₄(F,OH)₂)

Chalcedony (Agate / Jasper Specimen)

Silicon Dioxide (SiO2)

Tumbled ruby-in-zoisite (likely)

Ruby-bearing zoisite; zoisite Ca₂Al₃(SiO₄)₃(OH), corundum ruby Al₂O₃

Sandstone

Arenite (SiO2 primarily)

Jasper (Iron-rich Chalcedony)

Jasper (Microcrystalline Silicon Dioxide, SiO2 plus iron oxide impurities)

Paving-concrete aggregate with a rounded stone

Polymictic gravel aggregate; the central clast appears to be weathered sandstone or volcanic rock

Sandstone (likely Quartzose Sandstone)

Arenite

White cabochon gemstone, likely milky chalcedony or opalite

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

Beaded gemstone bracelet, likely lapis lazuli and pale quartz/agate

Lapis lazuli: lazurite-rich rock, chiefly (Na,Ca)₈(AlSiO₄)₆(S,SO)₂; pale beads are uncertain

Fossilized Shark Tooth (Eroded)

Carcharodon sp. or Otodus sp. fragment (likely)

Weathered chert or chalcedony nodule

Microcrystalline quartz (SiO₂), possibly silicified limestone or agate-like chalcedony

Engineered Quartz (Quartzite look-alike)

Silicon Dioxide (SiO2) composite

Fulgarite

Fulgurite (Lechatelierite / Vitrified Sand)

Sandstone

Sedimentary Rock (Quartz Sandstone)

Faceted gemstone in a jewelry setting

Indeterminate from image; likely quartz, cubic zirconia, or another transparent faceted stone

Red Sandstone

Quartz Arenite (iron-stained) / SiO2

Sandstone

Arenite

Likely iron-rich rock or weathered metallic mineral fragment

Uncertain; possibly limonite/goethite or iron-bearing slag

Green sea glass or green glass-like tumbled material

Amorphous silicate glass; likely anthropogenic soda-lime glass, not a natural mineral

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Flint / Chert

Microcrystalline Quartz (SiO2)

Sandstone

Arenite (specifically sublithic or quartz arenite)

Tumbled greenstone (likely serpentinite or green jasper)

Serpentinite, commonly dominated by serpentine-group minerals (Mg₃Si₂O₅(OH)₄); exact identification requires testing