Artifact

Quartz (worked as a tool or artifact)

Silicon Dioxide (SiO2)

André's Landing Rock (Sandstone Boulder)

Newark Supergroup Sandstone (likely Stockton Formation)

Rounded metallic-looking pebble, likely iron-rich rock or slag

Uncertain; possible limonite/goethite-rich ironstone, hematite-bearing material, or industrial slag

Chert / Flint Arrowhead

Microcrystalline Quartz (SiO2)

Brown chert or flint fragment

Microcrystalline quartz (SiO₂), commonly termed chert; exact identification requires testing

Flint or chert flake

Microcrystalline quartz (SiO₂), likely fossiliferous or cortex-bearing chert

Obsidian (likely)

Volcanic glass; chiefly silica-rich rhyolitic composition (approximately 70–75% SiO₂)

Obsidian (likely snowflake or banded variety)

Volcanic glass, primarily SiO₂

Obsidian (likely black volcanic glass)

Obsidian; naturally occurring rhyolitic glass, primarily SiO₂

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Banded Chert (Flint)

Cryptocrystalline Quartz (SiO2)

Chert (River Stone/Pebble)

Chert (SiO2)

Likely chert or weathered flint fragment

Microcrystalline quartz (SiO₂), possibly chalcedony-rich chert

Brown chert or silicified limestone fragment

Microcrystalline quartz (SiO₂), possibly occurring as chert; exact identification requires testing

Red jasper flint/chert knapped point

Microcrystalline quartz (SiO₂), chiefly chalcedony with iron-oxide coloration

Chert Nodule in Limestone

Microcrystalline Quartz (SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (specifically a Lithic Flake)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert or chalcedony fragment

Microcrystalline quartz (SiO₂), possibly jasper or agate

Dark flint or chert fragment

Microcrystalline quartz (SiO₂), commonly called flint when dark and nodular

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)

Dark gray rounded stone, possibly basalt or slag

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

Black obsidian arrowhead

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

Weathered sandstone pebble

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

Basalt

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

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

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)

Jadeite Jade

NaAl(Si2O6)