Anthropogenic Specimen (Man Made)

Paper (Cellulose)

Cellulose (C6H10O5)n

Turquoise

Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O

Milky quartz

Quartz (silicon dioxide, SiO₂)

Chert (Arrowhead variety)

Chert (SiO2)

Green Agate

Silicon dioxide (SiO₂)

Goldstone (Red/Brown)

Aventurine Glass (SiO2 with Copper inclusions)

Chalcedony (likely agate)

Microcrystalline quartz, SiO₂; agate is banded chalcedony

Brick

Fired clay or Ceramic material (no specific mineralogical scientific name as it's a composite)

Corundum (Sapphire/Ruby in Matrix)

Corundum (Al2O3)

Chert (Arrowheads)

Microcrystalline Quartz (SiO2)

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Polished amethyst-bearing quartz

Quartz, SiO₂; purple coloration from irradiation and trace iron

Diamond (as featured in jewelry)

Diamond (C - pure carbon)

Greenstone Celt (Polished Stone Axe)

Metamorphosed mafic rock (often Basalt or Diabase)

Cupronickel (on a 1981 Mexico 20 Pesos coin)

Copper-Nickel Alloy (Cu75Ni25)

Diamond (Cut and Polished)

Diamond (pure Carbon, C)

Flint (gray chert)

Microcrystalline quartz (SiO₂), a variety of chert

Mystic Topaz

Aluminum silicate fluoride hydroxide with titanium coating (Al2SiO4(F,OH)2)

Land Snail Shell

Gastropoda (Calcium Carbonate, CaCO3)

Chert (Arrowhead Fragment)

Silicon Dioxide (SiO2)

Likely flint (dark chert)

Microcrystalline quartz (SiO₂), commonly called chert or flint

Fossilized gastropod (likely nerite or related sea snail)

Gastropoda; shell composed originally of aragonite/calcite, commonly replaced or infilled by calcite

Fossil or modern bivalve shell

Calcium carbonate shell, likely aragonite (CaCO₃); exact species cannot be determined from the image

Diamond Druzy (Crystalline Diamond)

Carbon (C)

Polished green-and-black banded cabochon (likely malachite imitation or dyed agate)

Uncertain; possible malachite (Cu₂CO₃(OH)₂), banded agate (SiO₂), or man-made glass

Quartzite

Metamorphic Quartzite (SiO2)

Chert (specifically Tan/Gray Chert)

Microcrystalline quartz (SiO2)

Tumbled blue chalcedony (possibly blue agate)

Microcrystalline quartz, SiO₂; chalcedony variety

Green sea glass or green glass-like tumbled material

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

Weathered concrete or cementitious slab (not natural rock)

Artificial calcium-silicate cement composite; likely Portland cement concrete

Diamond (Cut jewelry specimen)

Diamond (pure Carbon, C)

Goldstone (blue/black aventurine glass)

Man-made aventurine glass; silica glass containing metallic copper or other glittering inclusions

Likely chert (flint)

Microcrystalline quartz (SiO₂), likely chert; exact identification is uncertain from the image alone

Flint (chert)

Microcrystalline quartz (SiO₂), a variety of chert

Yellow cabochon gemstone, likely citrine or yellow glass imitation

Quartz (SiO₂), if natural citrine; visual evidence is insufficient to exclude man-made glass or resin

Green glass cabochon or tumbled stone

Indeterminate; likely man-made glass, possibly aventurine glass rather than a natural mineral

Blue goldstone beads

Man-made aventurine glass (silica glass with metallic copper inclusions), not natural lapis lazuli

Kidney Stone

Calcium oxalate, uric acid, struvite, or cystine

Granite Pebble

Granite (Phaneritic intrusive igneous rock comprising Quartz, Feldspar, and Mica)

Chert (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)

Unidentified gray metallic object

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

Brown chert (flint)

Microcrystalline quartz (SiO₂), varieties called chert or flint