Slag
What is Slag?
Slag is a non-metallic by-product of smelting or glass creation. Slag can range from glassy to dull and stony in appearence, and has been used in construction, road building, and even jewelry design. The first record of the uses of slag has been found in ancient Egypt. Nowadays, slag with vibrant colors and unique patterns is a popular choice for decorative purposes.
Discover Values
Market Value Factors
Pricing varies for every rock and mineral, so use these universal factors to gauge Slag before comparing listings or appraisals.
Size & Weight
Larger, intact specimens usually command higher prices.
Rarity & Demand
Scarce material or popular varieties sell at a premium.
Condition & Finish
Chips, repairs, and heavy wear lower value; clean prep helps.
Treatment & Provenance
Untreated specimens with documented locality are prized.
Slag Localities Map
See where Slag is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.
Health & Safety Information
- ⚠️Others
- ⚠️Slag is safe to handle except in powder form. Some slag contains high levels of heavy metals like chromium, arsenic, and lead, which can be toxic if inhaled as dust. It's recommended to wear a dust mask during dust-generating activities like cutting or polishing.
Quick Facts
Physical Properties
- Color
- Various colors, typically black, gray, brown, blue, green
- Hardness (Mohs)
- 5.5 - 7
- Luster
- Vitreous, Dull
- Crystal System
- Amorphous
Chemical Properties
Also Known As
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Slag FAQs
How do I identify Slag?
Slag can be identified by its hardness of 5.5 - 7 on the Mohs scale, Various colors color, Vitreous, Dull luster, Amorphous crystal system. Look for these key characteristics when examining specimens.
What color is Slag?
Slag typically appears in Various colors, typically black, gray, brown, blue, green. Color can vary depending on impurities and formation conditions.
How hard is Slag?
Slag has a hardness of 5.5 - 7 on the Mohs scale. This gives it moderate hardness.