blind coal
Noun: - A type of coal: "blind coal" refers to anthracite, a hard, glossy, and non-bituminous coal that burns with little smoke or flame. It is often called "hard coal" and is known for its high carbon content and clean-burning properties.
- (Anthracite was mined for its high energy output.)
- (Anthracite is chosen for its clean combustion.)
"blind coal seam": a geological layer of anthracite that may be difficult to detect or access.
- Geologists discovered a rich blind coal seam beneath the limestone. (A hidden layer of anthracite was found.)
"to burn blind coal": to use anthracite as fuel, often in specialized stoves or furnaces.
- The old furnace was designed to burn blind coal efficiently. (The furnace was built for anthracite.)
Anthracite (n): the formal term for blind coal, a hard, compact variety of coal.
- Anthracite is the highest rank of coal. (It has the greatest carbon content.)
Coal (n): a combustible black or brownish-black sedimentary rock used as fuel.
- Blind coal is a specific type of coal. (It is a subcategory of coal.)
- Hard coal: a synonym emphasizing its physical hardness.
- Anthracite: the scientific and common term for blind coal.
"To be as black as blind coal": a poetic or old-fashioned idiom meaning extremely dark or black.
- The night sky was as black as blind coal. (The darkness was profound.)
"To sell blind coal": an archaic phrase meaning to trade anthracite, often implying a straightforward, no-nonsense transaction.
- The merchant specialized in selling blind coal to factories. (He dealt in anthracite for industrial use.)