Artifact

Gray flint/chert flake or tool

Microcrystalline quartz (SiO₂), commonly chalcedony

Dark fine-grained stone, likely basalt

Basalt; chiefly plagioclase feldspar and pyroxene, commonly with minor olivine and iron oxides

Polished black stone, possibly basalt or black obsidian

Likely fine-grained basalt (plagioclase and pyroxene) or volcanic glass (obsidian; rhyolitic composition)

Chert (specifically Flint or Dark Chert)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Tan/Buff Chert)

Microcrystalline Quartz (SiO2)

Chert (or potentially massive Quartz/Quartzite)

SiO2 (Silicon Dioxide)

Sandstone (Ferruginous)

Sandstone (SiO2 with iron oxide impurities)

Chert (Arrowhead/Artifact Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartz (worked as a tool or artifact)

Silicon Dioxide (SiO2)

Chert (Arrowhead Fragment)

Microcrystalline Quartz (SiO2)

Flint or chert knapped tool/flake

Microcrystalline quartz (SiO₂), likely chert/flint

Chert or flint fragment

Microcrystalline quartz (SiO₂), commonly chalcedony with cryptocrystalline quartz

Chert (often called Flint)

Chert (Microcrystalline Quartz, SiO2)

Chert (Chalcedony/Agate variety)

Microcrystalline Quartz (SiO2)

Chert (Flint Nobule)

Silicon Dioxide (SiO2)

Chert (Flint)

Chert (Microcrystalline or cryptocrystalline Quartz, SiO2)

Chert (Iron-Stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Jasper / Flint / Chert

Microcrystalline Quartz (SiO2)

Basalt Arrowhead (worked stone)

Aphanitic mafic volcanic rock (Basalt)

Flint or chert, possibly a knapped stone tool

Microcrystalline quartz (SiO₂), commonly chalcedony with possible carbonaceous impurities

Greenstone / altered mafic rock

Likely chlorite–actinolite schist or metabasalt; exact identification requires testing

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)

André's Landing Rock (Sandstone Boulder)

Newark Supergroup Sandstone (likely Stockton Formation)

Weathered chert or novaculite (flaked stone tool/fragment possible)

Microcrystalline quartz (SiO₂); likely chert, possibly Arkansas novaculite

Chert (likely a small flake)

Microcrystalline quartz (SiO₂); the flake-like shape alone does not establish whether it is naturally fractured or worked

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