A very fine saline film forms on the surface of the lamp, which is then evaporated by the heat generated by the lamp. This process of evaporation releases negatively charged ions to the atmosphere.
Salt alone, of natural substances, creates a negative ion release from interaction with atmosphere moisture and water. For instance, the negative ions generated at the seaside by the lively air/water interaction there brings renewal to the energy balance of the body. Salt Crystal Lamps work on the same principle, boosting free negative ions by as much as 300%.
Therefore the balance of negative ions and positive ions around us greatly affects how we feel. When the correct ratio of positive and negative ions is achieved, we feel calmer and more alert and energised.