industrial byproduct
Iron Slag
Anthropogenic Iron Silicate
Hardness: 6-7 (Mohs), Color: Charcoal grey to reddish-brown, Luster: Sub-metallic to vitreous (glassy), Structure: Amorphous/Vesicular, Cleavage: None, Specific Gravity: 2.8 - 4.0
Identified More industrial byproduct →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (Mohs), Color: Charcoal grey to reddish-brown, Luster: Sub-metallic to vitreous (glassy), Structure: Amorphous/Vesicular, Cleavage: None, Specific Gravity: 2.8 - 4.0
Formation & geological history
Formed as a byproduct of the smelting process where ore is separated from metal; cooling of molten impurities creates this glass-like rock.
Uses & applications
Historically a waste product; modernly used in road construction, concrete aggregate, and as a low-cost abrasive.
Geological facts
Slag is often mistaken for meteorites due to its burnt appearance and holes; however, the presence of bubbles (vesicles) and glass-like flows usually indicates industrial origin.
Field identification & locations
Identify by looking for spherical gas bubbles, flow textures, and localized magnetic properties. Commonly found near historical ironworks, railroads, and industrial sites.
More like this
Other industrial byproduct specimens
Cullet (Slag Glass)
Amorphous Silica (Industrial byproduct)
mineraloid
Blue Slag Glass
Amorphous Silica (Industrial byproduct)
Antropogenic (Man-made glass byproduct)
Slag Glass (Cullet Glass)
Amorphous Silica (Industrial byproduct)
mineral
Terracotta (Man-made ceramic brick fragment)
Baked clay / High-iron ceramic (Silicate-based ceramic)
Anthropogenic material (Man-made sedimentary mimic)
Slag (Industrial Byproduct)
Artificial silicate/iron byproduct
Mineral description (Anthropogenic material)
Cullet Glass (Slag Glass)
Amorphous Silicon Dioxide (Industrial Byproduct)
mineraloid