Though we don’t know if the theory behind this proves true in reality – a company called Nordic Rock is producing actual Swedish pure rock to be used as ice.  The idea is you freeze the rock for one hour, put it in your drink, and your drink will never be watered down.  The rock is pure, pollution free and eco-friendly.  Rinse, and re-use.  Set of 10 with leather pouch included.  $25  BUY