Anthropogenic (Man Made Artifact)

Note: Item is not a geological specimen

Guitar Components (Steel, Nickel, Plastic, Wood)

Chert (Lithic Artifact)

Microcrystalline Quartz (SiO2)

Goldstone (blue/black aventurine glass)

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

Small clear crystal, possibly quartz or glass-like gemstone

Uncertain; likely quartz (SiO₂), but the image is insufficient to exclude man-made glass or cubic zirconia

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

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

Green glass cabochon or tumbled stone

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

Polished blue-green glassy slag or coated mineral fragment

Most likely man-made colored glass/slag; exact composition cannot be determined visually

Blue goldstone beads

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

Quartzite (Lithic Artifact)

Quartzite (SiO2)

Chert (Arrowhead Artifact)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert / Flint Arrowheads and Artifacts

Cryptocrystalline quartz (SiO2)

Likely weathered metallic mineral or slag fragment

Uncertain; possibly limonite/goethite-coated iron mineral, or industrial iron slag

Basalt

Basalt (Mafic volcanic rock)

Painted River Pebble (likely Basalt or Greywacke)

Aphanitic Lithic Clast with Anthropogenic Pigment coating

Chert (Jasper/Flint variety)

Microcrystalline quartz (SiO2)

Rounded weathered pebble

Likely fine-grained sandstone, siltstone, or weathered volcanic rock; exact identification is uncertain from the image

Basalt

Basalt (Mafic volcanic rock)

Possible tektite or volcanic glass specimen

Natural silica glass; composition commonly near SiO₂, but exact identification requires chemical testing

Chert (Arrowhead/Projectile Point)

Cryptocrystalline Quartz (SiO2)

Obsidian Arrowhead

Obsidian (volcanic glass, SiO2 rich)

Asphalt (Bituminous Concrete)

Asphaltum / Bitumen-Aggregate Matrix

Colorless faceted gemstone, likely glass or cubic zirconia

Uncertain; possible cubic zirconia (ZrO₂) or quartz (SiO₂), but the image may show a man-made simulant

Colorless faceted quartz-like gemstone

Likely quartz (SiO₂), though the appearance may also indicate man-made glass or cubic zirconia

Chert Pebble

Microcrystalline Quartz (SiO2)

Chert

Microcrystalline or cryptocrystalline quartz (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (Likely Jasper)

Microcrystalline Quartz (SiO2)

Chert (Cream Variety)

Microcrystalline silica (SiO2)

Chert (often called Flint in dark varieties)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Jasper/Chalcedony)

Microcrystalline Silica (SiO2)

Chert (Flint/Jasper variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert / Flint Pebble

Chert (SiO2)

Chert (or Chalcedony)

Microcrystalline Quartz (SiO2)

Mahogany Obsidian

Volcanic Glass (Amorphous Silicon Dioxide with Hematite inclusions)

Chert (Flint) Artifact

Silicon Dioxide (SiO2)

Dyed Pink Dragon Vein Agate

Silicon Dioxide (SiO2) with artificial dye additives

Vesicular iron-rich slag or weathered metallic ore

Indeterminate; likely Fe-oxide-bearing slag (magnetite/hematite) rather than a specific natural mineral

Slag (Industrial Byproduct)

Ferro-silicate glass (Slag)

Sea Glass (Frosted Glass)

Amorphous Silica (SiO2) with various additives

Iron Slag

Ferrous slag (primarily silicates and oxides of calcium, iron, and magnesium)

Slag

Ferrous Slag (Siliceous industrial waste)