Finely ground rock salt or Kala namak is well-known to add taste to fruit chats, curd and salads. In truth it is used to add taste in some of the chats. In India, through fasts, it is a custom to break the speedy with food having salt as one of the ingredients.
Sodium chloride, trace impurities of sodium sulphate, sodium bisulfate, sodium bisulfite, sodium sulphide, Iron sulfide and hydrogen sulfide.