Black salt, known as kala namak in hindi is a commonly used ingredient in many Indian cuisines. Its unique flavour enhances the taste of many dishes.
 
Black salt is used in many Indian and Asian cuisines as a flavour enhancer. Indian kala namak goes in many dishes such as pickles, salads, chutneys, raitas, and fruit salads.
 
Black salt, also known as Himalayan black salt, Indian black salt or kala namak, is a volcanic rock salt manufactured in the regions surrounding the Himalayas. It contains, in addition to sodium chloride (the key chemical compound of salt), traces of sulphur compounds naturally found in the Himalayan mountains. 
This sulphur content is what gives the salt its unique pungent smell and tangy taste, reminiscent of rotten eggs. Indian black salt can vary in colour - some may not be even black at all.