Harvia R-991Sauna Heater Stones, Rounded Olivine, 5 10cm, 33lbs Rounded Olivine Diabase sauna heater stones resemble nature's rounded stones from the great rapids, bringing a softer tone to your sauna along with multiple benefits. This stone introduces a soft steam method; the pouring water runs easily down to the lower stone layers. This way the water reaches more surface area, generating more steam with a softer touch. This method of using rounded stones on the