An hourglass measures time, this time is measured in diamond grains. The 1"x 1/2" oval charm can turn to start the time again, the grains will fall to the bottom.The back is solid  and can be customized with engraving. There are two 1mm diamonds on the sides, and the hourglass is covered by a faceted quartz stone.   It has a Clasp at the top of charm and can easily attach to your favorite chain.