Soapstone originates from volcanic material. It is very dense – 1m3 = 3000kg – and this mass is one of the reasons why soapstone is so good at retaining heat for such a long period of time. Soapstone has a very high melting point of 1630 degrees celsius, and this makes it virtually heat resistant.
The soapstone used to make Tulikivi fireplaces is a natural stone, and its colour fluctuates slightly, which means that every Tulikivi is absolutely unique. Our most popular made-to-measure stoves include heated benches, for the warmest seat in the house. This is usually favoured by household pets! Because soapstone does not get too hot, you can be sure of a warm seat for up to 24 hours.
Soapstone has a better thermal conductivity compared to other materials due to its dense structure and mineral composition. This characteristic enables balanced and rapid warming throughout the soapstone structure.
The specific heat capacity of soapstone is about 1 J/gK and its density about 3 g/cm³, making its volumetric heat capacity 3 J/cm³K. The mineral magnesite has good thermal conductivity and heat capacity. The specific heat capacity for natural stone is usually 0.84 J/gK, making the value for soapstone about 20% greater than average.
There are over a hundred known soapstone deposits in Finland, most of which are in Eastern Finland. Finnish geologist Benjamin Frosterus, one of the founders of Finska Täljsten Ab (Suomen Vuolukivi Oy), surveyed Eastern Finland’s soapstone reserves as far back as the turn of the 20th century. He decided on the soapstone area in Juuka, which is held to be one of the best in the world in terms of quantity and quality. The majority of Tulikivi’s soapstone is quarried from this area.
Tulikivi is the only producer which tests stones on a regular basis by the IBR (Institut für Baubiologie Resenheim) so you can be sure that your stove is safe, both for the users and the builders. These stones are so long lasting that there are stoves in Finland which have lasted hundreds of years.