Tumbled black stone, likely black obsidian
Obsidian (volcanic glass; chiefly silica-rich rhyolitic composition)
igneous
Category
Mineral (Man Made Glass)
Browse mineral (man made glass) specimens identified by the Rock Identifier community.
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Obsidian
Volcanic Glass
igneous
Sea Glass
Man-made silicate glass
sedimentary
Sea Glass
Man-made silicate glass
sedimentary
Polished blue glassy mineral specimen, likely sodalite or blue aventurine
Most consistent with sodalite (Na₈Al₆Si₆O₂₄Cl₂), though dyed quartzite or blue glass cannot be excluded from the photograph
mineral
Sea Glass
Man-made silicate glass
gemstone
Opalite
Man-made opalescent glass
gemstone
Opalite
Man-made Glass (Synthetic Opalized Glass)
mineral
Obsidian
Volcanic Glass
igneous
Carved opalite pendant
Opalite (man-made opalescent glass; not a natural mineral)
gemstone
Blue Slag Glass
Man-made Silicon Dioxide (Amorphous)
Anthropogenic (Man-made)
Opalite Egg
Synthetic Glass (Simulated Opal)
mineral
Blue glassy gemstone-like specimen
Indeterminate; possibly dyed or treated turquoise, blue apatite, or man-made glass
gemstone
Cullet Glass (Slag Glass)
Amorphous Silicon Dioxide (SiO2) with metallic oxide impurities
mineraloid
One Pound Coin (UK)
Nickel-Brass Alloy (Cu-Zn-Ni)
mineral
Tumbled Clear Quartz/Rock Crystal
Silicon Dioxide (SiO2)
mineral
Opalite
Synthetic Opalized Glass / Man-made Glass
gemstone
Rose Quartz and Cherry Quartz (Dyed Glass/Quartz)
Silicon Dioxide (SiO2) with inclusions/dye
gemstone
Blue Obsidian
Volcanic Glass (Amorphous)
gemstone
Red glassy gemstone, possibly garnet
Unidentified red transparent material; garnet group (X₃Y₂(SiO₄)₃) is a possibility
gemstone
Milky quartz (likely)
Quartz, silicon dioxide (SiO₂)
mineral
Opalite
Synthetic Glass (typically Silica/Magnesium based with metal additives)
mineral
Tumbled milky quartz
Quartz — silicon dioxide (SiO₂), cryptocrystalline or microcrystalline variety possible
mineral
Sea Glass
Man-made vitreous material
gemstone
Slag Glass
Amorphous Silicate (Man-made)
industrial byproduct
Quartz crystal fragment (likely milky quartz)
Quartz, silicon dioxide (SiO₂)
mineral
Not a geological specimen
N/A (man-made object)
N/A
Sea Glass
Man-made vitreous material / Silicon dioxide
mineral
Blue Goldstone
Aventurine Glass
man-made glass
Metal Chain Belt with Square Plates
Not applicable (man-made)
Man-made Object (Metalwork)
Cullet Glass (Slag)
Amorphous Silicon Dioxide (Man-made)
Mineraloid
Opalite-style glass pendant
Man-made opalescent glass (not natural opal)
mineral
Tumbled milky quartz
Quartz (SiO₂), cryptocrystalline-to-massive variety
mineral
Blue Goldstone
Man-made glass with crystalline copper/cobalt inclusions
mineral
Polished opalite (likely man-made opalescent glass)
Opalite is a commercial name, not a mineral; typically opalescent glass, often soda-lime silicate glass
mineral
Clear Quartz Sphere (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Green Quartz / Chrysoprase / Sea Glass
Silicon Dioxide (SiO2)
mineral
Tumbled milky quartz pebble
Quartz (silicon dioxide, SiO₂), opaque-to-translucent milky variety
mineral
Opalite
Synthetic Glass (Simulated Opal)
gemstone
Opalite
Synthetic Glass / Man-made Opal Simulant
gemstone
Opalite (a synthetic glass)
Silicon Dioxide (SiO2) with various additives; not a true mineral but a man-made gem simulant
Mineral Simulant (Synthetic Glass)
Opalite
Synthetic Opalised Glass
mineral