Abstract Soapstone occurs in Finland within Precambrian greenstone belts in the eastern parts of the country. Nunnanlahti and other deposits near Lake Pielinen are the best known and most important of these occurrences. This soft stone is highly workable. Soapstone was one of the most popular ornamental rocks used in architecture of the Jugend (Art Nouveau) style in St Petersburg, Russia, Helsinki, Finland, and in other northern European cities at the end of the nineteenth and into the early twentieth centuries.

Abstract St Petersburg was founded in 1703. Between 1703 and the 1830s, buildings of baroque and classicism styles were faced with stones from the NW part of the Russian Empire. In 1840s–1910s, many new types of ornamental stones from different European countries were added to the faces of buildings of so-called eclecticism and modernism styles. The map of deposits shows 32 main sources of stone. This report gives a chronological review of the use of natural stone in the architecture of St Petersburg, Russia, in 1703–2009. The map of deposits and a list of rock types are given.