Man Made Composite (Lithified Equivalent Of Sedimentary)

Opalite

Synthetic Glass, SiO2 base with metallic inclusions

Black Obsidian

Amorphous volcanic glass (SiO2 + impurities)

Aura Quartz (Titanium/Gold coated)

Silicon Dioxide (SiO2) with metallic vapor deposition

Polished white chalcedony or quartz pendant

Microcrystalline quartz (chalcedony), SiO₂; exact identification is uncertain from the image

Iron Slag

Iron/Steel Slag (Ferrosilicate Glass)

Iron Slag (Industrial Byproduct)

Anthropogenic Vitrification Product/Ferrous Slag

Polished black stone, likely obsidian

Obsidian (volcanic glass; mostly silica-rich rhyolitic composition)

Green obsidian (likely molded or heat-treated glass-like specimen)

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

Pet Rock (Man-made Quartzite or Granite Cobble)

Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica

Blue opal heart cabochon

Common opal, hydrated amorphous silica (SiO₂·nH₂O), likely blue-dyed or synthetic opalite

Slag (Industrial Glass/Glassy Rock)

Anthropogenic Vitreous Material

Sea Glass (White/Clear)

Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO

Aura Quartz

Titanium/Titanium-Gold treated Silicon Dioxide (SiO2)

Red Slag Glass

Amorphous Silica (Industrial byproduct with metallic oxide dopants)

Metal Alloy (Likely Pewter or Sterling Silver)

Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).

Green sea glass or tumbled green quartz (uncertain)

Likely quartz (SiO₂) if natural; alternatively man-made soda-lime glass

Green Aventurine

Quartzite with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)

Slag

Ferrous Slag (Amorphous calcium-magnesium-aluminum silicates)

Botryoidal chalcedony (likely agate/jasper variety)

Microcrystalline quartz, SiO₂

Polished silver sheen obsidian heart

Obsidian (volcanic glass), primarily rhyolitic silica-rich glass

Opalite

Synthetic Opalised Glass

Carborundum (Silicon Carbide)

Silicon Carbide (SiC)

Man-made Jewelry (Metal and Glass/Plastic)

Synthetic Alloy and Amorphous Solid (SiO2/Polymer)

Red-orange cabochon, likely carnelian or glass imitation

Carnelian: chalcedony (microcrystalline SiO₂), commonly iron-colored

Polished black pebble, possibly obsidian

Volcanic glass (obsidian), likely; identification is tentative from the image

Conglomerate

Conglomerate (clastic sedimentary rock)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Titanium Amethyst Geode

Silicon Dioxide (SiO2) with Titanium/Metal Vapor Deposition Layer

Green Glass (often marketed as 'Obsidian' or 'Green Quartz')

Amorphous Silica (SiO2) with copper or chromium additives

Blue-green cabochon, likely chalcedony or treated glass imitation

Cryptocrystalline quartz (chalcedony/possibly chrysoprase); identification uncertain from image

Blue Obsidian

Volcanic Glass (SiO2 with inclusions)

Green glass sphere/marble

Soda-lime glass (primarily SiO2, Na2O, CaO)

Green sea glass (likely bottle glass)

Man-made soda–lime silicate glass; not a natural mineral

Sea Glass

Amorphous silicon dioxide (Man-made glass weathered by nature)

Blue glassy tumbled stone, likely blue chalcedony or slag glass

Chalcedony (microcrystalline SiO₂), possibly man-made blue glass

Green sea glass (likely bottle glass)

Man-made soda-lime silicate glass; not a natural mineral

Sea Glass

Amorphous Silicon Dioxide (Man-made glass weathered by nature)

Milky quartz (rough fragment)

Quartz, silicon dioxide (SiO₂)

Rock crystal (clear quartz), possibly cloudy quartz

Quartz, silicon dioxide (SiO₂)

Goldstone (Red)

Aventurine Glass (SiO2 + Cu)

Ferro-slag (Leland Blue/Slag Glass)

Anthropogenic Vitreous Silica (Industrial Slag)

Blue Crackle Quartz (Dyed Quarzite)

Silicon Dioxide (SiO2) with artificial dye