metamorphic
Anthracite Coal
Anthracite
Hardness: 2.5-3; Color: Jet black to silver-grey; Luster: Submetallic, vitreous; Crystal Structure: Amorphous (non-crystalline); Specific Gravity: 1.3-1.8; Conchoidal fracture.
- Hardness
- 2
- Color
- Jet black to silver-grey
- Luster
- Submetallic, vitreous
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Physical properties
Hardness: 2.5-3; Color: Jet black to silver-grey; Luster: Submetallic, vitreous; Crystal Structure: Amorphous (non-crystalline); Specific Gravity: 1.3-1.8; Conchoidal fracture.
Formation & geological history
Formed through the low-grade metamorphism of bituminous coal. It represents the highest coal rank, created under intense pressure and heat within the earth's crust over millions of years (Carboniferous to Permian periods).
Uses & applications
Used primarily as a high-grade fuel for residential and industrial heating, in the production of high-purity carbon, and occasionally as a gemstone in mourning jewelry or ornamental carvings.
Geological facts
Anthracite contains the highest percentage of fixed carbon (86%-98%) and the lowest amount of impurities among all coal types. It burns with a short, blue, smokeless flame.
Field identification & locations
Identify by its hardness and shiny, almost metallic luster that doesn't rub off on fingers like lower-grade coals. Found in folded mountain belts like the Appalachians in Pennsylvania, USA, or parts of South Wales and China.
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