metamorphic
Anthracite Coal
Anthracite (Carbon based fossil fuel)
Hardness: 2.5–3 on Mohs scale; Color: Black to steel gray; Luster: Sub-metallic to vitreous; Crystal Structure: Amorphous (non-crystalline); Specific Gravity: 1.3–1.8.
- Hardness
- 2
- Color
- Black to steel gray
- Luster
- Sub-metallic to vitreous
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 2.5–3 on Mohs scale; Color: Black to steel gray; Luster: Sub-metallic to vitreous; Crystal Structure: Amorphous (non-crystalline); Specific Gravity: 1.3–1.8.
Formation & geological history
Formed through the regional metamorphism of bituminous coal. It involves extreme pressure and heat applied to organic plant matter buried in sedimentary basins, typically dating to the Carboniferous period (300-360 million years ago).
Uses & applications
Primarily used as a high-grade fuel for domestic and industrial heating due to its high carbon content and low impurity levels. Also used for water filtration and as a pigment/additive in some industrial processes.
Geological facts
Anthracite contains the highest carbon content (86%–97%) of all coal types. Because it burns with a blue flame and produces very little smoke or soot, it was historically referred to as 'hard coal' or 'black diamond.'
Field identification & locations
Identify in the field by its high luster (very shiny compared to other coal), lack of soot when handled, and its hardness (it doesn't crumble easily). Commonly found in the Appalachian Mountains of Pennsylvania, USA, and parts of Wales and China.
More like this
