A box contains soapstone, quartzite, and dunite, 10 kg each. These stones have different levels of heat capacity. Lay quartzite, the least heat-capacious stone, on the bottom of the stove for quicker warmup. Dunite goes as the mid-layer, and the most capacious (and beautiful) soapstone forms the upper layer. This makes a balanced mix of stones, which differ in terms of thermal, physical, and litho therapeutic properties.