Himalayan Rock Salt (Sendha namak) is exctracted from Khewra Salt Mine. It is believed that this salt have been formed millions of years ago from evaporation of ancient water bodies. Though rock salt is minimally processed and is free of additives when compared to table salt but even then rock salt mostly comprises of NaCl (sodium chloride).
It is estimated that Rock salt may contain up to 84 different minerals and trace elements but the amount is close to negligible. While iodized table salt cost about Rs. 16/kg, rock salt fetches a hefty premium with around Rs. 75/kg.
Is it worth spending 4.5 times the amount for rock salt?
From the above comparison, it is evident that though amount of Calcium, Magnesium, Potassium, Iron is more in rock salt than table salt but the difference is insignificant and are unlikely to provide any additional health benefits whatsoever. Moreover, one may end up having iodine deficiency by preferring rock salt over table salt. One can occasionally consume rock salt but switching over it completely for health benefits makes no sense.