mineraloid
Leland Blue Stone
Anthropogenic Iron Smelting Slag
Hardness: 5.5-6.5 (glassy). Color: Green, teal, blue, or purple. Luster: Vitreous to dull. Structure: Amorphous (non-crystalline). Common features: Air bubbles (vesicles), swirl patterns, and conchoidal fracture.
- Hardness
- 5
- Color
- Green, teal, blue, or purple
- Luster
- Vitreous to dull
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Physical properties
Hardness: 5.5-6.5 (glassy). Color: Green, teal, blue, or purple. Luster: Vitreous to dull. Structure: Amorphous (non-crystalline). Common features: Air bubbles (vesicles), swirl patterns, and conchoidal fracture.
Formation & geological history
Formed as a byproduct of the iron smelting process during the late 19th century (1870-1884) in Leland, Michigan. Raw iron ore was heated with limestone and charcoal; the impurities melted into this colorful, glass-like slag.
Uses & applications
Used primarily for artisan jewelry such as necklaces, rings, and earrings. It is also a popular collector's item for those visiting the Great Lakes region.
Geological facts
While it looks like a natural stone, it is actually industrial waste from the Leland Lake Superior Iron Co. It has become a legendary find for beachcombers on Michigan's 'Leelanau Peninsula'.
Field identification & locations
Identify by looking for air bubble pits and vibrant teal/green colors on beaches near Leland, Michigan. It feels like thick glass and often has a semi-translucent quality when held to light.
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