The soothing, deep glow given off by these lamps can help to promote sounder, more fulfilling sleep and leave you feeling recharged and energized. Even better, as with all our lamps, these release negative ions into the air, helping to promote a healthy atmosphere wherever they are placed. The Grey color of these unique lamps comes from a rare vein of Himalayan Salt. Although these lamps are predominately grey, white salt and/or amber salt may be present due to varying concentration of minerals.