Flexi Says: The pumice rock is used in the production of lightweight concrete blocks. When the concrete is mixed, the space in pumice rock remains partially filled with air that helps in reducing the weight of the block. Lighter concrete blocks decrease the structural steel requirements to form a building. The trapped air also gives the blocks a greater insulating value. The pumice rock also finds usage as a drainage rock and soil conditioner in plantations. Pumice stone is used to smooth your skin. The intake of the pumice rocks was also found to have the capabilities of softening nodules and was later used with other herbal ingredients to treat gallbladder cancer and urinary difficulties.