man-made glass / industrial byproduct
Cullet Glass / Slag Glass
Amorphous silica glass
Hardness 5.5-6 on Mohs scale, vitreous luster, conchoidal fracture, transparent to translucent, vibrant blue color.
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Physical properties
Hardness 5.5-6 on Mohs scale, vitreous luster, conchoidal fracture, transparent to translucent, vibrant blue color.
Formation & geological history
Man-made material, typically a byproduct of glass manufacturing or decorative chunks produced for landscaping and decoration.
Uses & applications
Used in landscaping, aquariums, decorative arts, and sometimes sold as a faux gemstone or "obsidian" to unsuspecting buyers.
Geological facts
Often mistaken for natural blue obsidian, which is extremely rare in nature. The bright, uniform color and complete lack of crystal structure confirm its artificial origin.
Field identification & locations
Identified by its conchoidal fracture, high transparency, lack of true crystal structure, and often the presence of spherical air bubbles. Common in landscaping supplies.
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