Not A Natural Rock

Basalt Pebble (Beach Pebble)

Mafic Volcanic Rock (Basalt)

Rounded river pebble (lithology unclear)

Indeterminate natural rock; no specific mineral or rock type can be identified from the image

Exposed shoreline bedrock and sediment

Unidentified natural rock; the image does not show enough detail for a specific geological identification

Decorative gemstone-chip jewelry (likely turquoise, coral, and assorted beads)

Predominantly turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; other pieces appear to be dyed coral or red stone, and possibly shell/metal components

Weathered gray rock fragment

Likely granitic or volcanic feldspathic rock; exact identification is uncertain from the image

Green sea glass (likely slag glass or bottle glass)

Man-made soda-lime silicate glass; not a naturally occurring mineral

Weathered, iron-stained rock (likely metamorphic)

Indeterminate from photograph; possibly quartz-rich gneiss or schist

Fossil fish in limestone

Indeterminate fossil teleost fish preserved in calcareous sedimentary matrix

Tumbled blue stone, likely blue aventurine or dyed chalcedony

Aventurine quartz (SiO₂) or chalcedony (microcrystalline SiO₂); exact identification requires testing

Goldstone and pink quartz bead strands

Goldstone is aventurescent copper-bearing glass; pink beads are likely rose quartz (SiO₂), though dyed or glass imitations are possible

Road-surface aggregate (crushed stone)

Unidentifiable mixed lithic aggregate; likely basaltic/andesitic fragments with feldspar, quartz, and weathered rock

Chipped Glass/Plastic Fragment

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

Ferruginous Slag (Iron Smelting Byproduct)

Fused Silicate Scoria (Amorphous mixture of FeO, SiO2, and CaO)

Obsidian-like volcanic glass (likely slag or natural obsidian)

Obsidian, primarily amorphous volcanic silica glass (approximately SiO₂); identification is uncertain from an image

Likely slag or metallic industrial byproduct

Unidentified iron-rich ferrous slag; possibly magnetite-bearing slag

Colorless faceted gemstone, likely cubic zirconia

Cubic zirconia (zirconium dioxide, ZrO₂); visual confirmation is unavailable

Possible slag or basalt fragment

Indeterminate dark mafic material; likely basalt (plagioclase–pyroxene) or industrial iron-rich slag

Gold bullion bars

Native gold (Au), likely cast or refined metal

Cut purple gemstone, likely synthetic cubic zirconia or glass

Undetermined; possible cubic zirconia (ZrO₂)

Faceted glass-like gemstone object

Likely synthetic glass or cubic zirconia; exact material cannot be confirmed from the image

ABS Plastic (Acrylonitrile Butadiene Styrene)

(C8H8)x·(C4H6)y·(C3H3N)z

Gemstone-set ring, likely cubic zirconia or diamond

Likely synthetic cubic zirconia (zirconium dioxide, ZrO₂); stones may alternatively be diamond (carbon, C)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Decorative opal-like turtle mosaic

Likely imitation or assembled opal material; exact stones cannot be confirmed visually

Polymer Clay (Mock Mineral)

Polyvinyl chloride (PVC) with plasticizers and pigment

Colorless faceted gemstone, likely cubic zirconia

Cubic zirconia (synthetic zirconium dioxide, ZrO₂); possibly colorless quartz or laboratory diamond

Sandstone

Sedimentary Clastic Rock (Quartz Arenite)

Polished tiger iron

Tiger iron, a banded aggregate of tiger’s-eye (quartz), red jasper, and hematite/magnetite

Possible iron-rich basalt or industrial slag

Basalt, likely Fe–Mg silicate rock; exact identification is uncertain from the blurred image

Iron-rich vesicular rock, possibly slag or basalt

Uncertain; likely basaltic rock (plagioclase–pyroxene–iron oxide) or industrial iron slag

Carved greenstone figure

Likely nephrite jade (jadeite is a possible alternative), mainly amphibole-group minerals

Asphalt aggregate pavement

Bituminous asphalt concrete containing crushed stone aggregate

Unidentified rock fragments

Indeterminate; likely a weathered, iron-stained silicate rock

Quartz Pebble

Silicon Dioxide (SiO2)

Asphalt Concrete

Bituminous Concrete / Asphaltic Composite

Polished multicolored stone bead bracelet

Likely dyed or treated agate/jasper, chiefly microcrystalline quartz (SiO₂)

Colorless faceted gemstone, likely synthetic cubic zirconia

Cubic zirconia (zirconium dioxide, ZrO₂); natural diamond is a less likely alternative

Greenstone / serpentinite carving

Serpentinite, chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile); exact identification requires testing

Blue sapphire ring

Corundum, Al₂O₃; blue color typically from trace iron and titanium

Paving-concrete aggregate with a rounded stone

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

Gemstone jewelry ensemble

Likely mixed gemstone and glass-bead jewelry; exact stones cannot be determined from the image

Banded Slag Glass (Leland Blue/Frankfort Green style)

Anthropogenic Glass Specimen (Amorphous Silicon Dioxide with impurities)