HIMALAYAN SALT CRYSTAL LAMPS ARE RECOMMENDED BY FENG SHUI EXPERTS & ARCHITECTS THEY ARE MADE OF 100% PURE CRYSTAL SALT WHICH WAS FOUND DEEP IN THE GROUND OVER 260 MILLION YEARS OLD WHICH GIVES LEAVES THE SALT PROTECTED FROM CONTAMINATION DURING THE MINING PROCESS THEY ARE MADE BY HAND IN SMALL VILLAGES WITH HIGHLY SKILLED CRAFTSMEN USING THERE FAMILY SKILLS TO PRODUCE BEAUTIFULL LAMPS FOR BEST RESULTS THEY ARE BEST LEFT ON UP TO 24HOURS AND SHOULD FEEL WARM BUT YOU CAN HAVE THEM ON FOR A COUPLE HOURS .