Antropogenic (Man-made industrial byproduct)
Ferrochrome Slag
Industrial Glassy Slag (Fe-Cr alloy byproduct)
Hardness: 6-7 (Mohs); Color: Dark grey to greenish-black with metallic flecks; Luster: Vitreous (glassy) to metallic; Crystal Structure: Amorphous/microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 3.0-4.0
- Hardness
- 6-7 (Mohs)
- Color
- Dark grey to greenish-black with metallic flecks
- Luster
- Vitreous (glassy) to metallic
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (Mohs); Color: Dark grey to greenish-black with metallic flecks; Luster: Vitreous (glassy) to metallic; Crystal Structure: Amorphous/microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 3.0-4.0
Formation & geological history
Formed as a byproduct of the smelting process in the production of ferrochromium. Molten waste is cooled rapidly, resulting in a dense, glassy material. Often found in areas with a history of steel or alloy manufacturing.
Uses & applications
Commonly used as construction aggregate, road base material, or abrasive grit for sandblasting. Some pieces are collected as 'curiosity' stones or 'meteor-wrongs' due to their metallic appearance.
Geological facts
Slag is frequently mistaken for meteorites because of its high density, dark color, and occasional magnetism. It often contains vesicles (small bubble holes) from trapped gases during cooling, which the specimen in the image appears to exhibit.
Field identification & locations
Identify by looking for air bubbles (vesicles), a glassy 'conchoidal' fracture, and unusual heaviness. It is commonly found near old railways, industrial sites, or used as gravel in rural roads. Collectors should test for magnetism and look for lack of a 'fusion crust' to distinguish from real meteorites.
More like this
Other antropogenic (man-made industrial byproduct) specimens
Ferrosilicon Slag (Industrial Vitrified Glass)
Vitreous Silicate Residue
Antropogenic (Man-made industrial byproduct)
Aluminum Slag
Anthropogenic Aluminum (Al)
mineral
Slag (Industrial Byproduct)
Artificial silicate/iron byproduct
Mineral description (Anthropogenic material)
Cullet Glass (Slag Glass)
Amorphous Silicon Dioxide (Industrial Byproduct)
mineraloid
Aluminum Slag
Anthropogenic Aluminum (Al)
mineral
Slag
Glassy silicate byproduct (anthropogenic material)
industrial byproduct