Natural Himalayan salt lamps are actually solid blocks of Himalayan salt that have been hand-carved. The color of Himalayan salt lamps ranges from a pink, Red, & Maroon with the hue a result of the mineral concentration. Within the hollowed-out center of this block of salt is a light bulb that emits both light and heat. A salt lamp is not a lamp at all if it doesn’t have the light and heat source within it. Without that, it’s just a block of salt.
Salt is hygroscopic, which means it attracts water molecules to itself. Being the big hunk of salt that it is, a Himalayan salt lamp is believed to work by attracting the water molecules. This water vapor can also carry indoor air pollutants like mold, bacteria and allergens. Once the water vapor comes in contact with the salt lamp, the pollutants are believed to remain trapped in the salt.