Tumblestone - Quartz, Crackle A single tumblestone measuring approximately 15mm - 25mm in size. £1.00 Quantity: at £1.00 each Add To Basket 0 in your basket View Basket Checkout Clear quartz which has been heated and dyed to display a beautiful ?cracked? effect. Said to amplify and transit subtle vibrations. It has the additional properties of Quartz.