Himalayan Black Salt

Kala namak, also known as Himalayan black salt, Sulemani namak, is a type of rock salt that is mined in Pakistan and India. Kala namak is often used as an ingredient when cooking because it has a distinctly sulphuric taste to go along with its salty flavor, which gives dishes like eggs or falafel their signature smell.
 
Often used by vegetarians as an addition to tofu for an egg substitute.