NunnaUuni has studied the stone structure of its soapstone deposit, as well as its heat qualities, for years. The strength of the stone in the deposit lies in its unique, strongly foliated talc structure, which provides the stone with its resistance to high temperatures and its outstanding thermal conductivity, as well as the resulting capacity for storing large amounts of energy.

This extensive stone deposit has been named the MammuttiStone deposit, and stone from it has been registered as MammuttiStone.

Studies indicate that the deposit contains approximately 15,000,000 m³ of MammuttiStone – enough for the next 500 years at the current production rate. The quality of the MammuttiStone deposit is very homogenous, and the stone is easy to detach. Therefore, the yield from the deposit is extremely good.

The MammuttiStone deposit is the foundation of NunnaUuni.	The picture shows the MammuttiStone parent rock which amounts to 15 million cubic metres. The dotted line on the map marks the boundaries of the Nunnanlahden Uuni Oy's  mining permit.