Evolution Salt’s artesian, hand carved massage stones are made of our ethically sourced, 100% natural & raw Himalayan Crystal Salt. These massage stones are exfoliating, mineralizing & gently detoxifying providing the ultimate, deep relaxation your body craves. The skin is our largest organ, absorbing minerals, as well as toxins; therefore there is enormous benefit in using Himalayan Crystal Salt Massage Stones over river stones. The magnesium content in salt stones help to relax muscles & melt away tension, while the 84 minerals & trace elements are beneficially absorbed to alkalize the body & gently draw out toxins. To Use: Heat your Evolution Salt massage stones in the microwave for 1 minute for the perfect, penetrating heat that will last an hour. Massage stones may also be chilled in the fridge or freezer for the perfect sports massage.