metamorphic
Anthracite Coal
Anthracite
Hardness: 2.5-3.0 Mohs; Color: Black or dark grey with a sub-metallic luster; Texture: Fine-grained and dense; Fracture: Conchoidal; Specific Gravity: 1.3-1.8.
- Hardness
- 2
- Color
- Black or dark grey with a sub-metallic luster
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Physical properties
Hardness: 2.5-3.0 Mohs; Color: Black or dark grey with a sub-metallic luster; Texture: Fine-grained and dense; Fracture: Conchoidal; Specific Gravity: 1.3-1.8.
Formation & geological history
Formed through the regional metamorphism of bituminous coal under intense heat and pressure over millions of years, typically during mountain-building events (orogenies) in the Carboniferous period.
Uses & applications
Used primarily for domestic and industrial heating, as a high-carbon additive in steelmaking, and occasionally for carving decorative ornaments and jewelry (jet).
Geological facts
Anthracite has the highest carbon content (86-97%) and the fewest impurities of all types of coal. It burns with a short, blue, smokeless flame.
Field identification & locations
Identify by its 'shiny' or metallic black appearance, relative hardness (non-sooty compared to bituminous coal), and lightweight feel. Commonly found in folded mountain belts like the Appalachians.
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