Anthropogenic Specimen (Man Made Material)

Fossilized coral with attached shell

Likely fossil coral (Scleractinia or Tabulata), with a bivalve or gastropod shell; exact identification requires microscopy

Chert (Arrowhead/Projectile Point)

Microcrystalline quartz (SiO2)

Chert (Common Opal/Jasper variety)

Cryptocrystalline Quartz (SiO2)

Amethyst crystal fragment

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

Red cabochon gemstone ring (likely glass or synthetic stone)

Undetermined; the image does not establish a natural mineral identity

Flint (chert) nodule

Microcrystalline quartz (SiO₂), occurring as a flint/chert nodule in limestone

Polished blue stone, likely sodalite or dyed agate

Sodalite: Na₈(Al₆Si₆O₂₄)Cl₂; exact identification requires testing

Chert (likely flint)

Microcrystalline quartz, SiO₂

Weathered fossil shell fragment

Indeterminate bioclastic carbonate, likely molluscan shell (calcium carbonate, commonly aragonite or calcite)

Likely tumbled epidote-bearing rock or green jasper

Epidote-group silicate, possibly in a jasper or serpentinite matrix

Fossil shark tooth in sediment

Likely fossilized shark tooth, possibly *Carcharhinus* or *Otodus*; exact identification requires the tooth’s full morphology and locality

Iron-stained quartz-rich rock, possibly jasper or chert

Microcrystalline quartz (SiO₂) with iron oxides/hydroxides

Quartz (Microcrystalline/Chert)

Silicon Dioxide (SiO2)

Asphalt Pavement (with aggregate)

Asphalt concrete

Green glassy slag (often sold as “sea glass” or “green obsidian”)

Industrial vitreous slag; primarily amorphous silicate glass, composition variable

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Chalk

Calcite (CaCO3)

Paving-concrete aggregate with a rounded stone

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

Chert Nodule

Microcrystalline Quartz (SiO2)

Ferrocoke or Slag

Anthropogenic pyrometallurgical residue

Polished hematite (specimen identification uncertain)

Hematite, α-Fe₂O₃

Fossil coral in limestone

Fossilized colonial coral, likely tabulate or favositid coral (CaCO₃), preserved in calcitic limestone

Dyed Crackle Quartz

Silicon Dioxide (SiO2) with synthetic dye

Cobalt Blue Slag Glass

Amorphous Silicon Dioxide (anthropogenic) with Cobalt additives

Tumbled yellow jasper or chalcedony

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

Painted River Pebble (likely Basalt or Greywacke)

Aphanitic Lithic Clast with Anthropogenic Pigment coating

Dyed Dragon Vein Agate

Silicon Dioxide (SiO2) with artificial pigment

Pale green aventurine (likely quartz) sphere

Quartz, SiO₂; possibly pale green aventurine, with color from inclusions or treatment

Sandstone (Quartzose)

Arenite (primarily SiO2)

Asphalt fragment

Bituminous concrete

Green iridescent glass cabochon or synthetic gemstone

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

Petrified Wood

Silicified Wood (primarily SiO2)

Bituminous Coal (with Anthracite or Vitrinite inclusion)

Organic-rich Sedimentary Rock (Carboniferous classification)

Faceted glass-like gemstone object

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

Chert (Yellow Jasper/Flint)

Microcrystalline Quartz (SiO2)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Chert Arrowhead (Lithic Artifact)

Microcrystalline Quartz (SiO2)

Chert Arrowhead

Cryptocrystalline Quartz (SiO2)

Blue Sapphire (Synthetic or Man-made Glass Imitation)

Corundum (Al2O3) if natural; Lead-glass or Spinal if synthetic

Chert (Common Variety, Jasper)

Microcrystalline Quartz (SiO2)

Diamond

Carbon (C)

Unidentified polished dark gemstone cabochon

Possibly hematite, obsidian, jet, or dark agate; image insufficient for a definitive identification