Lava Stone Jewellery is the next big thing.  The dark, porous beads made from lava stone have become a bit of a fashion trend over the last few years, but the benefits don’t stop at adding a little dimension to your bracelet stack.  
Some use them as diffuse jewellery. Simply place 1-2 drops of your favourite essential oils and rub it in. 
Don't worry about them fitting you as they stretch - one size fits all.