Under the name of heritage stone are included those natural stones that have special significance in the human culture, as the stones that have been used for centuries to build the architectonic heritage of world sites, some of them recognized by UNESCO for their importance in humanity culture.

Some of these stones are no longer extracted or even the extraction was stopped for millennia. Other stones continue to be commercially important, but their heritage uses have not been well documented in widely available sources for the interested parties.
The public details about the “Global Heritage Stone Resource” (GHSR) designation were first time provided in August 2008 at the 33rd International Geological Congress in Oslo, when it was also agreed to advance the GHSR proposal under the auspices of “Commission C-10 Building Stones and Ornamental Rocks” of the International Association for Engineering Geology and the Environment (IAEG) (link).

The defining characteristics of a Global Heritage Stone Resource are:

  • Special significance or recognition of the nominated stone in human culture, potentially association with national identity or a significant individual contribution to architecture;
  •  Historic use of the proposed stone for a period of at least 50 years;
  •  Wide-ranging geographic application;
  •  Utilisation in significant works, in public or industrial projects (buildings, sculpture or utilitarian applications);
  • Ongoing availability of material for quarrying (at least for restoration purposes);
  • Scientific, cultural, architectural, environmental and commercial benefits arising from designation as Global Heritage Stone Resource (GHSR).

The oolithic and clastic limestones from Magura Calanului historical quarry are the most important and relevant stone presenting a high and easy recognizable heritage value. It is considered to be the main source of stone for blocks used on the monumental structures of Sarmizegetusa Regia, the capital of the Dacian Kingdom, and to the ensemble of fortresses and fortifications around it. These fortresses were located in a mountainous area, over 1000 m altitude, on a geological substratum (schistous or limestony) that cannot be cut to size for building purposes. For this reason, the Dacians used the oolithic limestone from Magura Calanului, located at 30-50 km away from the fortresses, with good workability as dimension (squared) stone. Fortunately, the quarry was only exploited during the ancient period and is well preserved, being probably one of the most spectacular ancient monuments of its kind outside of the Greek-Roman world.
There are other types of stone in Romania with heritage value, the most known being Ruschita marble, Moneasa, Vașcău, Podeni, Savadisla, Albești, Codru Babadag or Năieni limestones, Bologa dacite, Moigrad microdiorite, Măcin granites, Pietroasa andesite, Geoagiu and Borsec travertines, Baschioi sandstone etc.). Their outstanding national and international significance are due to the ornamental characteristics, sustained also by their durabilities in public or private works, historical or modern ones.
But to prove their heritage value, it is mandatory to document not only their qualitative performances, but also references to their places of application or consistent details related to historical buildings or monuments with special significance in human culture.