Smokey Quartz - very protective and grounding stone. It is said to bring physical and psychic protection. Absorbs negative energy and thought patters aids in over coming stress, fear, jealousy, and depression. Safe Material - 18/8 (304) food grade stainless steel + 100% natural crystal. The straw unscrews into two pieces for cleaning. Cleaning brush included. Dimension - Straw length: 7.9". Crystal size: Length about 1.65”-1.7”(42-43mm)/ Width about 0.98”(25mm). Please note that crystals are natural, each stone may vary slightly with shape, size, color and transparency, each crystal is different and unique.