Quartzite – is volcanic crystalline rock specie. This stone is ideal for the sauna heaters and wood burning stoves. It heats up very quickly and retains the heat for a long time.
Diabase also has sufficient stability to withstand prolonged exposure of high temperature. The stone hardly absorb water and shows a low coefficient of thermal expansion. This means that any changes in temperature or water exposure will not harm the rock. Red Diabase will last longer than other average sauna stones.