mineral

Aluminum Slag

Anthropogenic Aluminum (Al)

Hardness: 2.5-3 (Mohs scale), Color: Silvery-white to dull grey, Luster: Metallic, Crystal structure: Face-centered cubic (though usually amorphous in slag form), Specific Gravity: ~2.7

Hardness: 2

Identified May 10, 2026More mineral →

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Physical properties

Hardness: 2.5-3 (Mohs scale), Color: Silvery-white to dull grey, Luster: Metallic, Crystal structure: Face-centered cubic (though usually amorphous in slag form), Specific Gravity: ~2.7

Formation & geological history

Formed as a byproduct of aluminum smelting or through the melting of aluminum cans/scrap in a high-temperature fire (pyrometallurgy). This is a man-made geological byproduct rather than a natural mineral.

Uses & applications

Usually recycled to recover the metal content; can be used as a source for aluminum oxide in refractories or abrasive manufacturing.

Geological facts

While aluminum is the most abundant metal in Earth's crust, it is never found as a free metal in nature due to its high reactivity; objects like this are always the result of human industrial processes or accidental fires.

Field identification & locations

Identified by its very light weight (low density) compared to other metals, silvery-grey color, and often bubbly or 'melted' texture. Frequently found near old industrial sites, foundries, or campfire residues.