Artifact

Flint pebble

Chert / Flint (SiO2)

Chert / Flint

Microcrystalline quartz (SiO2)

Greywacke (River Slikkenstone)

Greywacke (Impure Sandstone)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (White Chert / Flint)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

Black obsidian arrowhead

Obsidian; volcanic glass, typically rhyolitic in composition (mostly SiO₂)

Dark gray rounded stone, possibly basalt or slag

Uncertain; likely fine-grained basalt (plagioclase–pyroxene) or iron-rich industrial slag

Basalt

Extrusive Mafic Igneous Rock (composed primarily of Plagioclase and Pyroxene)

Weathered sandstone pebble

Sandstone, likely quartz-rich (arkose or quartz arenite)

Jadeite

NaAlSi2O6

Jadeite Jade

NaAl(Si2O6)

Turquoise and Red Coral

CuAl6(PO4)4(OH)8·4H2O (Turquoise) and Corallium rubrum (Red Coral)

Sandstone concretion

Sedimentary concretion

Flint or chert fragment

Microcrystalline quartz (SiO₂), commonly with chalcedony and minor impurities

Chert or flint flake

Cryptocrystalline microcrystalline quartz (SiO₂), likely chert/flint

Gray-green flint/chert fragment

Microcrystalline quartz (SiO₂), likely chert or chalcedony-rich material

Rounded river pebble

Indeterminate lithic clast; likely weathered sandstone or quartz-rich sedimentary rock

Chert or flint nodule

Microcrystalline quartz (SiO₂), commonly chalcedony with possible opaline silica

Chert (Arrowheads)

Microcrystalline Quartz (SiO2)

Jasper (likely red jasper or brecciated chert)

Microcrystalline quartz/chalcedony, SiO₂, colored mainly by iron oxides

Obsidian (likely black obsidian)

Volcanic glass; predominantly rhyolitic silica glass (SiO₂-rich)

Chert or flint fragment

Microcrystalline quartz (SiO₂), commonly called chert; darker varieties are termed flint

Flint (chert), possibly worked

Microcrystalline quartz; SiO₂ (chalcedony/quartz aggregate)

Blue-gray flint or chert fragment

Microcrystalline quartz (SiO₂), likely flint/chert

Dark flint or chert fragment

Microcrystalline quartz (SiO₂), likely flint/chert

Flint

SiO2 (Cryptocrystalline Quartz)

Jade Bangle (Jadeite)

Jadeite, NaAlSi2O6

Polished black stone, likely black obsidian

Obsidian (volcanic glass), chiefly silica-rich rhyolitic composition

Flint

SiO2 (Microcrystalline Quartz / Chert)

Flint

Cryptocrystalline Quartz (SiO2)

Flint

Microcrystalline quartz (SiO2)

Flint

Cryptocrystalline quartz (SiO2)

Flint

Microcrystalline Quartz (SiO2)

Chert / Flint

Microcrystalline quartz (SiO2)

Chert

Microcrystalline quartz (SiO2)

Diorite

Intermediate intrusive igneous rock

Carnelian or Red Agate

Chalcedony (SiO2)

Lapis Lazuli

Lapis Lazuli (contains lazurite, calcite, pyrite)

Green Jade

Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (NaAlSi2O6)

Jadeite

NaAl(Si2O6)

Green Jadeite

Jadeite, NaAl(Si2O6)

Beads (likely glass or man-made material)

N/A (artificial material)