Question

What variety of coal is sometimes called 'black diamond,' because it is the hardest and most pure coal in the world?

1) Anthracite
2) Bituminous
3) Lignite
4) Peat

Answer 1

Anthracite coal is sometimes called 'black diamond' because it is the hardest and most pure coal in the world.

Step-by-step explanation:

The variety of coal that is sometimes called 'black diamond' because it is the hardest and most pure coal in the world is anthracite coal.