Black Salt (Kala Namak) is a type of rock salt that has a dark, almost black color. It is used as a seasoning in Indian cuisine and has a very pungent, sulfurous smell. Kala Namak is high in sulfur content and is known for its digestive properties. It is also said to have detoxifying effects and can be helpful in weight loss programs. Black Salt can be used to add flavor to salads, vegetables, and fish.