Mineraloid
Cullet Glass (Man-made Glass Slag)
Amorphous Silica (SiO2) with chemical additives
Hardness: 5.5-6 on Mohs scale; Color: Vibrant green (due to iron or chromium additives); Luster: Vitreous (glassy); Structure: Amorphous (non-crystalline); Cleavage: None (exhibits conchoidal fracture); Specific Gravity: 2.4-2.8.
- Hardness
- 5
- Color
- Vibrant green (due to iron or chromium additives)
- Luster
- Vitreous (glassy)
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Physical properties
Hardness: 5.5-6 on Mohs scale; Color: Vibrant green (due to iron or chromium additives); Luster: Vitreous (glassy); Structure: Amorphous (non-crystalline); Cleavage: None (exhibits conchoidal fracture); Specific Gravity: 2.4-2.8.
Formation & geological history
Formed as a byproduct of industrial glass manufacturing or as recycled waste material (cullet) that has been melted and cooled. It is not geological in origin and can be modern or decades old depending on the site of discovery.
Uses & applications
Used in decorative landscaping, aquarium gravel, recycled glass production, or sold as 'andara crystals' or 'sea glass' in the metaphysical and craft markets.
Geological facts
While often mistaken for minerals like emerald or peridot, this specimen is clearly glass due to its high transparency, conchoidal (shell-like) fracture patterns, and the presence of small internal gas bubbles which do not occur in natural crystals.
Field identification & locations
Identify in the field by looking for air bubbles, lack of crystal faces, and smooth, curved fracture surfaces. Commonly found near old factory sites, riverbeds, or beaches. It is a common 'leaverite' (leave it right there) for serious mineral collectors but popular for crafts.
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