Question

Black Gold
What is called as black gold?

Answer 1

petroleum is said as black gold

Answer 2

Black gold:

It is a term applied to:

\implies⟹ Oil

\implies⟹ Petroleum

It is black, when it comes out of the ground.

Prior to the mid 19th century, oil from animal tallow was used as a fuel.

Petroleum is black gold.

Oil is great for a country's economy, for example gold.