metamorphic
Anthracite Coal
Anthracite
Hardness: 2.5-3.0 on Mohs scale; Color: Black to steel gray; Luster: Submetallic, vitreous (glassy); Structure: Amorphous (non-crystalline); Fracture: Conchoidal; Specific Gravity: 1.3-1.4
- Hardness
- 2
- Color
- Black to steel gray
- Luster
- Submetallic, vitreous (glassy)
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 2.5-3.0 on Mohs scale; Color: Black to steel gray; Luster: Submetallic, vitreous (glassy); Structure: Amorphous (non-crystalline); Fracture: Conchoidal; Specific Gravity: 1.3-1.4
Formation & geological history
Formed through the regional metamorphism of bituminous coal. It involves the subjection of organic plant matter to high temperatures and pressures over millions of years (primarily Carboniferous period), resulting in a high carbon content (86-97%).
Uses & applications
High-grade fuel for domestic and industrial heating, filtration media for water purification, and occasionally used for decorative carvings or jewelry specimens.
Geological facts
Anthracite is the highest rank of coal. It burns with a short, blue, and smokeless flame. Unlike other coals, it feels relatively clean to the touch and does not leave thick black soot on fingers.
Field identification & locations
Identify in the field by its high luster (shinier than other coal), conchoidal fracture, and comparative hardness. Commonly found in folded mountain belts like the Appalachian Mountains in Pennsylvania, USA.
More like this
