Anthropogenic Material

Iron-rich rock fragment, possibly weathered hematite-bearing basalt

Likely basalt with iron oxides/hydroxides; composition may include hematite (Fe₂O₃) or goethite (FeO(OH))

Quartzite

Quartzite (SiO2)

Likely weathered brown stone, possibly iron-rich sandstone or chert

Indeterminate from image; possible ferruginous sandstone (quartz + iron oxides) or iron-rich chert

Blue calcite (probable)

Calcite, CaCO₃

Black Onyx and Mother of Pearl

Cryptocrystalline Quartz (SiO2) and Nacre (Calcium Carbonate)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Limestone and Quartz Gravel with Petrified Wood

Sedimentary gravel aggregate and fossilized wood

Jasper

Microcrystalline Quartz (SiO2)

Fossil Shark Tooth

Chondrichthyes (Class)

Blue Goldstone

Man-made glass with crystalline copper/cobalt inclusions

Jasper

Silicon dioxide (SiO2)

Amethyst

Quartz (SiO₂), purple variety colored mainly by iron impurities and irradiation

Tumbled rose quartz

Quartz, silicon dioxide (SiO₂), rose-colored variety

Flint Pebble

SiO2 (Microcrystalline Quartz / Chalcedony)

Jasper or Agatized material

Microcrystalline Quartz (SiO2)

Sandstone or Limestone

Sedimentary Rock

Flint

SiO2 (Microcrystalline Quartz / Chert)

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Serpentinized ultramafic rock (likely serpentinite)

Serpentinite; chiefly serpentine-group minerals (chrysotile, lizardite, antigorite), with olivine/pyroxene relics and possible magnetite

Diamond (Cut Gemstone)

Carbon (C)

Gravel and Sand Aggregate

Unconsolidated Clastic Sediment

Crushed Granite and Quartz Gravel

Composite Igneous and Silicate Rock Aggregate

Crushed Stone Ballast

Crushed Limestone or Granite Aggregate

Coal

Combustible sedimentary rock

Sand

Siliciclastic sediment / Quartz sand (SiO2)

Dragon Vein Agate (Dyed/Treated)

Agate (SiO2)

Petrified Wood

Petrified Wood (Silicified Wood)

Sandstone

Clastic Sedimentary Rock

Likely citrine or yellow glass imitation in a silver-tone bracelet

Citrine: quartz, SiO₂; exact material cannot be confirmed visually

Milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Asphalt / Road Aggregate

Bituminous Conglomerate (synthetic)

Fossiliferous Chert (with Fossil Shells)

Silicon Dioxide (SiO2) with biogenic inclusions

Polished pink quartz specimen

Quartz, SiO₂; possibly rose quartz or pink chalcedony

Yellow Jasper

Silicon Dioxide (SiO2) with iron inclusions

Tumbled red-purple quartzite or jasper

Quartz-rich quartzite/chalcedony aggregate (SiO₂), possibly iron-stained

Tumbled green gemstone, likely dyed howlite or serpentine

Most consistent with dyed howlite (Ca2B5SiO9(OH)5); exact identification requires testing

Tumbled serpentine-rich stone

Serpentinite, commonly dominated by antigorite, lizardite, or chrysotile

Botryoidal chrysocolla with possible malachite and quartz

Chrysocolla, hydrated copper aluminosilicate; commonly intergrown with malachite, Cu₂CO₃(OH)₂, and quartz, SiO₂

White quartz-rich rock, likely quartzite or milky quartz fragment

Quartzite; predominantly quartz (SiO₂), possibly with minor feldspar or mica

White quartz-rich rock, likely quartzite

Quartzite; predominantly microcrystalline quartz (SiO₂), possibly with minor feldspar, mica, or iron oxides

Blue cabochon gemstone, likely synthetic glass or dyed stone

Indeterminate from image; possible glass, synthetic spinel, sodalite, or lapis lazuli

Orange-brown tumbled mineral specimen

Indeterminate; possibly iron-stained chalcedony, quartz, or jasper