Candle Holder Himalayan Salt Natural Hand Carved " Heart ". The salt crystals associated with the light source produce negative ions. These neutralize the positive ions in the air carried by molds, allergens and bacteria. This helps to purify the air of a room. Positive ions are produced by the electronic equipment of our house. They can cause all kinds of problems and diseases such as allergic reactions, increased levels of stress and insomnia. The negative ions produced by the lamps neutralize these problems.