Anthropogenic Specimen (Man Made)

Tree Agate

Chalcedony (SiO2)

Iron-rich banded quartzite / jaspilite

Banded iron formation (BIF), chiefly quartz (SiO₂) and iron oxides (hematite, Fe₂O₃; magnetite, Fe₃O₄)

Diorite (River Pebble)

Intermediate Phaneritic Igneous Rock

Diamond (in a cluster setting)

Crystallized Carbon (C)

Cobalt Blue Sea Glass

Amorphous Silica Glass (SiO2 + CoO)

Chert (possibly a worked stone flake)

Microcrystalline quartz, SiO₂

Petrified Wood (Silicified Wood)

Silicified Paleoflora (mainly Quartz, SiO2)

Tumbled obsidian

Volcanic glass; chiefly SiO₂, noncrystalline

Chert (varieties include Flint and Jasper)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (River Siltstone/Quartzite type)

Microcrystalline Quartz (SiO2)

Possible basalt or iron-rich slag

Basalt (tentative; identification uncertain from image)

Dyed Blue Agate Slice

Silicon Dioxide (SiO2)

Sea Glass

Amorphous Silicon Dioxide (SiO2)

Crackle Glass (Simulated Gemstone)

Amorphous Solid (SiO2)

Blue Goldstone

Synthetic glass with copper or cobalt/manganese inclusions

Blue Goldstone

Synthetic Aventurescent Glass (Cobalt-doped soda-lime glass)

Blue Goldstone

Aventurine glass (Synthetic borosilicate glass with cobalt and metallic inclusions)

Green Glass Slag

Amorphous Silicon Dioxide (SiO2) with metal oxide impurities

Porcelain (Stoneware Ceramic)

Mullite / Silica-glass composite (Al6Si2O13)

Glass Nugget (Tumbled Glass)

Amorphous Silicon Dioxide (SiO2) with additives

Goldstone (Brown)

Aventurine glass

Smoky Quartz

Smoky Quartz (Silicon Dioxide, SiO2)

Granite

Granite (phaneritic felsic intrusive rock)

Aura Quartz / Rainbow Aura Quartz

Silicon Dioxide (SiO2) with metallic vapor coating

Pyrite

Iron Sulfide (FeS2)

Carved red jasper bead (likely ceramic imitation)

Jasper, microcrystalline quartz (SiO₂); exact material uncertain from the image

White cabochon gemstone, likely milky chalcedony or opalite

Chalcedony: microcrystalline quartz, SiO₂; appearance may also indicate synthetic opalite glass

Pyrite

Iron Disulfide (FeS2)

Tumbled purple quartz, likely amethyst or lavender quartz

Quartz (SiO₂), probably iron-colored amethyst; exact variety uncertain from the image

Chert (and/or Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Tumbled milky quartz pebble

Quartz (SiO₂), likely milky quartz

Dark gneiss or migmatitic amphibolite

Band ed gneiss; composition likely quartz–feldspar–biotite/amphibole, possibly migmatite

Polished black obsidian

Volcanic glass; primarily rhyolitic SiO₂, with minor iron, magnesium, and other trace elements

Possible basalt or industrial iron-rich slag

Basalt (plagioclase–pyroxene rock); identification uncertain from image

Quartzite

Quartzite (SiO2)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Diamond (or Cubic Zirconia simulant)

Carbon (C) - Diamond / Zirconium dioxide (ZrO2) - CZ

Note: Item is not a geological specimen

Polyester mesh and Ethylene-vinyl acetate (EVA) polymer

Gemstone bead necklace (likely citrine or yellow quartz)

Quartz, SiO₂; precise identification is uncertain because the beads are blurred and metal settings obscure them

Fossiliferous limestone

Bioclastic limestone, predominantly calcite (CaCO₃)

Green aventurine bead bracelet

Quartz (SiO₂), typically green quartzite/aventurine colored by fuchsite mica or other inclusions

Diamond

Carbon (C)