mineral
Blue Slag Glass
Anthropogenic Amorphous Silicon Dioxide
AI-generated identification · may be incorrectHardness: 5.5-6.5 (Mohs scale), Color: Cobalt blue, Luster: Vitreous, Structure: Amorphous (non-crystalline), Cleavage: None (conchoidal fracture), Specific Gravity: 2.4-2.8
- Hardness
- 5
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Physical properties
Hardness: 5.5-6.5 (Mohs scale), Color: Cobalt blue, Luster: Vitreous, Structure: Amorphous (non-crystalline), Cleavage: None (conchoidal fracture), Specific Gravity: 2.4-2.8
Formation & geological history
Formed as a byproduct of the iron smelting process, specifically when limestone, iron ore, and fuel are heated together; common in industrial areas from the 19th and early 20th centuries.
Uses & applications
Historically a waste product, but now used for landscaping, decorative gravel, aquarium decor, and vintage jewelry collecting.
Geological facts
Slag glass, also known as 'Leland Blue' in Michigan specifically, is highly sought after by beachcombers despite being a man-made industrial byproduct.
Field identification & locations
Identify by its glass-like bubbles (vesicles), conchoidal (shell-like) fracture patterns, and vibrant colors not typically found in native rocks of the same region.
