Man Made Glass

Polished silver sheen obsidian heart

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

Aventurine Quartz

Silicon Dioxide (SiO2) with Fuchsite inclusions

Polished black pebble, possibly obsidian

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

Tumbled clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Strawberry Quartz

Silicon Dioxide (SiO2) with Hematite or Goethite inclusions

Moldavite

Tektite (Impact Glass), ~80% SiO2 + Al2O3

Likely clear quartz pebble or glassy quartz fragment

Quartz (silicon dioxide, SiO₂)

Clear quartz fragment (rock crystal)

Quartz, silicon dioxide (SiO₂)

Rock crystal (clear quartz), possibly cloudy quartz

Quartz, silicon dioxide (SiO₂)

Milky quartz (rough quartz fragment)

Quartz, silicon dioxide (SiO₂)

Blue opalite glass cabochon (likely imitation opal)

Man-made opalescent glass; not a natural mineral

Blue glassy-looking specimen, possibly dyed or coated mineral

Not identifiable from the photograph; possibilities include dyed quartz or glassy slag, but composition cannot be established visually.

Blue Sapphire (Synthetic or Man-made Glass Imitation)

Corundum (Al2O3) if natural; Lead-glass or Spinal if synthetic

Obsidian (likely black volcanic glass)

Obsidian; primarily amorphous volcanic silica glass, approximately SiO₂-rich rhyolitic composition

Raw quartz crystal

Quartz (silicon dioxide, SiO₂), likely milky or included quartz

Likely tumbled or cut quartz/chalcedony fragment

Silicon dioxide (SiO₂), probably microcrystalline quartz or quartz

Rock crystal quartz fragments

Quartz (silicon dioxide, SiO₂)

Strawberry Quartz

Silicon Dioxide (SiO2) with Hematite/Goethite inclusions

Clear quartz tumbled stone

Quartz (silicon dioxide, SiO₂)

Likely polished quartz or glass-like mineral cabochon

Probably quartz (SiO₂), though the image cannot exclude man-made glass

Likely clear quartz crystal or glass-like gemstone

Quartz, silicon dioxide (SiO₂); exact identification is uncertain from the strongly magenta-lit image

Polished obsidian

Volcanic glass; predominantly rhyolitic SiO₂

Agate and millefiori glass jewelry

Agate: microcrystalline quartz (SiO₂); millefiori element appears to be man-made glass

Black tumbled stone, possibly obsidian

Obsidian (volcanic glass; predominantly SiO₂), identification uncertain from image

Blue glassy mineral specimen, possibly dyed or synthetic

Uncertain; possible blue fluorite (CaF₂), dyed chalcedony, or man-made glass

Quartz crystal (likely clear quartz)

Quartz, silicon dioxide (SiO₂)

Polished black stone, likely black obsidian

Obsidian (volcanic glass), chiefly silica-rich rhyolitic composition

Polished white chalcedony or quartz pendant

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

Iron Slag

Iron/Steel Slag (Ferrosilicate Glass)

Tumbled gray stone, likely quartz-rich pebble

Probable microcrystalline quartz/chalcedony (SiO₂), possibly gray jasper or quartzite

Green Aventurine

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

Libyan Desert Glass

Impact-melt silica glass (SiO2 + traces of Al, Fe, Ti)

Slag

Ferrous Slag (Amorphous calcium-magnesium-aluminum silicates)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Polished black stone, likely obsidian

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

Opalite

Synthetic Opalized Glass (SiO2 + additives)

Tumbled black obsidian (likely)

Volcanic glass; chiefly silica-rich rhyolitic glass (SiO₂)

Opalite

Man-made Synthetic Glass (Silicon Dioxide with metal additives)

Green sea glass (likely)

Man-made glass, likely soda-lime silicate glass; not a natural mineral or rock

Cullet Glass (Slag Glass)

Amorphous Silicon Dioxide (SiO2) with metallic oxide impurities

Opalite (a synthetic glass, often confused with Opal)

Silicon dioxide glass (SiO2nH2O, for natural opal)

Black beaded bracelet, likely black onyx or glass

Possibly chalcedony (microcrystalline quartz, SiO₂); the beads may instead be man-made glass