Anthropogenic (Man Made Artifact)

Obsidian

Obsidian (Volcanic Glass)

Gray flint or chert fragment

Microcrystalline quartz (SiO₂), likely chert/flint

Quartzite

Quartzite (primarily Silicon Dioxide, SiO2)

Chert (specifically Flint or Jasper variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Worked chert (likely flint)

Microcrystalline quartz/chalcedony, SiO₂

Chert Nodule (Commonly known as a Flint or River Cobble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Chert / Flint Pebble

Silicon Dioxide (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Goldstone

N/A (Synthetic Glass with Copper Inclusions)

Blue tumbled glass-like specimen; likely blue slag glass

Likely man-made glass (silicate glass), not a natural mineral; exact material cannot be confirmed from the image

Flint or chert fragment

Microcrystalline quartz (SiO₂), likely flint/chert

Chert (Flint)

Cryptocrystalline Quartz (SiO2)

Diamond

Carbon (C)

Luminous Stone (Glow-in-the-dark Synthetic/Man-made Stone)

Strontium Aluminate tinted glass or resin (Crystalline silicate/oxide mix)

Obsidian

Obsidian (volcanic glass)

Obsidian (Arrowhead Lithic Tool)

Obsidian (Amorphous Volcanic Glass / SiO2 + inclusions)

Diamond (in a jewelry setting)

Diamond (Carbon, C)

Nephrite Jade

Nephrite

Malaysian 50 Sen Coin

Coinage (specific alloy unknown without metallurgical analysis, but typically brass or bronze for this denomination and era)

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

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

Native American Hammerstone / Pitted Stone

Modified lithic artifact (often quartzite, basalt, or granite)

Gray flint/chert flake or tool

Microcrystalline quartz (SiO₂), commonly chalcedony

Blue Slag Glass

Amorphous Silica (Byproduct of smelting)

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)

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

Flint or chert knapped tool/flake

Microcrystalline quartz (SiO₂), likely chert/flint

Quartz (worked as a tool or artifact)

Silicon Dioxide (SiO2)

Jasper / Flint / Chert

Microcrystalline Quartz (SiO2)

Chert or flint fragment

Microcrystalline quartz (SiO₂), commonly chalcedony with cryptocrystalline quartz

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)

Dark flint or chert fragment

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

Diamond (or Diamond Simulant)

Carbon (C)