Abstract The Global Heritage Stone Resource (GHSR) and Global Heritage Stone Province (GHSP) designations provide a means by which geoscientists, planners and industry can explain the importance of some types of stone in the repair and maintenance of historic structures, new building and objects such as sculptures. Defining criteria are envisaged as including: wide ranging geographical use for a significant period; utilization in significant industrial projects; recognition as a cultural icon; continuing availability; and potential benefits of designation. Consideration is needed of the future composition and administration of the overseeing Board, refinement of the mechanism for making and approving nominations and how to consult the cultural heritage sector on nominations. It is likely that a larger panel of reviewers will be needed to support the work. It is important that criteria are clear and widely known and that discussions and decisions are well documented and publicly available. A mechanism for appeals against decisions is also needed. It is considered that the cultural heritage qualification should be the primary criterion supported by timescale and scale of use, both geographically and quantitatively.

Abstract The proposal to designate those natural stones that have achieved widespread utilization in human culture was first mooted in late 2007, and first presented in a public forum at the 33rd International Geological Congress in July 2008. Over the next four years, a network of international correspondents was created, circulars were distributed, a website was established and formal rules were adopted, all with the focus of establishing the ‘Global Heritage Stone Resource’ designation. During the 34th International Geological Congress in July 2012, the Heritage Stone Task Group was formally established under the auspices of the International Union of Geological Sciences, in association with the International Association of Engineering Geology and the Environment, Commission C-10 Building Stones and Ornamental Rocks, and with a formal Board of Management. It has now been recognized that the new designation has value both in offering a mechanism to promote the safeguarding of stone resources, as well as in the formal definition of stone types within sufficiently tight parameters that it can facilitate name protection. For the future, the Board of Management needs to encourage and approve nominations for the new designation. As well, an annual conference needs to be organized.

Abstract Larvikite is a peculiar and unique monzonitic rock originating in the Carboniferous–Permian Oslo Rift, SE Norway. The blue iridescence in the feldspar crystals made the rock particularly attractive as ornamental stone, and since the start of industrial scaled production in 1884, the use of larvikite has reached every corner of the global community. With resources for hundreds of years, the region will produce larvikite blocks far into the future. The production of larvikite has changed significantly during the last decades, towards more sustainable production finding new applications and markets for excess rock in the quarries. The significance of larvikite in the global market has also created a wider appreciation of the rock in the Norwegian society, acknowledging the rich history of larvikite production and use.

Abstract Cited documents indicate that industrial production of building stones of the Hallandia gneiss from SW Sweden (Halland County) goes back to at least the 1850s when large quantities of paving stones were exported to Germany and Denmark. It is most likely that quarry operations have been going on for a much longer period, mostly for local needs. The Hallandia gneiss is an aesthetically distinct gneiss unit characterized by multiple phases of deformation and veining at high-grade metamorphic conditions, unique with few, if any, equivalents in the world. Remnants of about 500 quarries (including small examples) have been documented in the area. The occurrence of Hallandia gneiss is limited to the coastal areas of SW Sweden where there are strong demands on the land for recreation and cultural heritage. The unique and restricted occurrence of the Hallandia gneiss to an area with strong competing interests of land use has resulted in severe concerns about the supply of this building stone material. The need to safeguard a future supply of this rare stone type is urgent. This paper provides an outline of its unique geology, historic and present use, along with its technical and aesthetical properties.

Abstract The Kolmården serpentine marble is a well known Svecofennian marble from Sweden, and here it is proposed as a possible ‘Global Heritage Stone Resource’. This marble matches the newly proposed designation ideally, since for many years it has been used in the construction of major historical buildings, as well as famous buildings of national and international importance. The Kolmården marble continues to be quarried today.

Abstract Paleozoic calcitic marbles are found in the Estremoz Anticline, Ossa-Morena Zone (Southern Branch of the European Variscides in Portugal). This 40 km NW–SE structure presents outcrop continuity and intense mining activity since the Roman Period. The structure has a Precambrian core and the younger rocks are from the Devonian Period. The marbles occupy an intermediate stratigraphic position in the Cambrian age Volcano Sedimentary Sequence. The Variscan Orogeny had two pulses with different intensities under ductile and brittle tension fields. The Alpine Cycle also caused more fracturing of the marbles. The geological features imprinted in the marbles are beautiful aesthetic patterns highlighted when used as dimension stone. Since the Roman period, pieces of art made with Estremoz Marble were exported abroad and can be found in museums and archaeological sites throughout Europe and North Africa countries. Present day, Estremoz Marble objects can be found all over the world. The very rich marble based heritage is omnipresent in cities, and the countryside is marked by intense mining activity side by side with rural industries; therefore the region has unique characteristics allowing the development of integrated industrial tourism routes, promoting sustainable development of industrial, scientific and technological cultural opportunities. The historical and widespread application of these marbles in national and international monuments, some of them already part of the UNESCO World Heritage Sites, is a condition to propose them as Global Heritage Stone Resource for their international recognition.

Abstract The historical centre of Oporto (Portugal), designated a UNESCO World Heritage of the Humanity, has been selected to illustrate the use of the local granite during the development of the city, invariably influencing the history, architecture, religion, culture and the personality of the local people. The Oporto monumental heritage goes back to Roman occupation: the city has been developed by the construction of granite buildings strongly implanted on a hard granite substrate. The Oporto profile gives an impressive grey architecture according to different styles of granite work that characterize the city in all its aspects. The description of selected sites within the historical centre, where it is possible to recognize the importance of the granite in the character of the city, aims to call attention to the inextricable role of geology in the built heritage and culture, as well as to diagnose the deterioration processes, enhanced by the environment and the anthropogenic activity, that affect houses and monuments as a consequence of the intrinsic properties of the granite. The Oporto granite genesis, responsible for the nature of the mineralogy assemblage, the physical properties and the degree of weathering, provides specific features that make this granite particularly suitable for the ornamental work that defines the town monumental constructions. The old city wall, the medieval and baroque churches, the neoclassic houses and also the small humble habitations are a few examples of the profuse stone heritage of which Oporto is proud.

Abstract Piedra Pajarilla is the local name under which the Martinamor granite was known when it was quarried during the 19th century. It is a leucogranite of Hercynian age, and here we present its formal nomination as a ‘Global Heritage Stone Resource’. Piedra Pajarilla fits the proposed designation because it has been used for centuries in the construction of major historical and famous buildings in Salamanca, leading the city to being included in the UNESCO World Heritage list in 1988. Piedra Pajarilla is no longer quarried, and this nomination will help to maintain the historical quarry for the restoration of the monuments if blocks need to be replaced.

Abstract Serpentinites from Sierra Nevada (Granada, south of Spain) have traditionally been used as ornamental elements in historical buildings, both indoors and outdoors. The cathedral, the Palace of Charles V, the Royal Chancellery in Granada and some others are good examples of their use. Outside Granada, the serpentinites are seen at the monastery of El Escorial, The Royal Palace and the convent of Las Salesas Reales, all of them part of Madrid’s architectural heritage, although there are much more examples to be found across the country. There are two quarries located in Sierra Nevada that supplied all the material to make the different elements in the above buildings. In this work, we report a thorough characterization of the main characteristics of the serpentinites from Sierra Nevada in order to propose this stone as a possible candidate as a ‘Global Heritage Stone Resource’. This work is important for duly recognizing a natural stone that has been profusely used in the past in the construction of a magnificent heritage of important cities, and historical quarries should be protected so that they can provide original material if required to do so in the future.

Abstract Villamayor Stone (VS) is an arkosic stone and is known by several names: (i) VS because the quarries are located in Villamayor de Armuña village (Salamanca, Spain); (ii) Golden Stone due to its patina, which gives the stone a ochreous/golden colour; (iii) Franca Stone is known locally and in historical documents. VS has several varieties ranging from channel to floodplain facies. In this work, we have selected three varieties. VS was quarried and used in the construction of Romanesque monuments such as the Old Cathedral, Gothic monuments including the New Cathedral and the University façade, and Baroque monuments, notably the Main Square. Also, VS was used in the reconstruction of the Roman Bridge (Salamanca, Spain). Currently, VS is quarried by a small number of family businesses, using traditional methods for cladding façades of new buildings. Unfortunately, part of the construction sector went bankrupt in the 2008 crisis. However, VS is still the main stone used in the city of Salamanca for the restoration of monuments, even though used in relatively small quantities in comparison with usage before the economic crisis. It is thus of great importance for future generations that their quarries and the craft of masonry be protected. This work proposes that VS should be designated as a Global Heritage Stone Resource.

Abstract Colmenar Limestone is one of the traditional materials most commonly used in monuments in Madrid, Spain. The petrophysical properties of this stone determine its high resistance to decay. Its low water absorption and pore size distribution favour good hydraulic behaviour, which is likewise furthered by its high ultrasound velocity and low anisotropy. The durability findings pursuant to the 280 freeze–thaw, 42 thermal shock, 30 salt crystallization and 120 salt mist cycles conducted confirmed the stone’s resistance to decay in these simulated aggressive environments. The mass loss recorded in the samples and the variation in petrophysical parameters were generally very low after all except the salt crystallization trials, which induced loss of cohesion on the stone surface, increased roughness and the formation of concentric microcracks, sub-parallel to the more exposed surface, that also affected the arris and vertices of the specimens tested.

Abstract Carrara Marble, from Italy, probably one of the most famous dimension stones in the collective memory and in ordinary people, is here nominated as a suitable ‘Global Heritage Stone Resource’. Quarried since pre-Roman times, the Carrara marble is the testimonial of an area/industry that was able – for a variety of reasons not easily repeatable in future stone history – from the dawn of the stone sector, to trigger a flywheel effect on a global scale. Suitable for any environment and cultural context, this versatile marble has been appreciated in almost any field of application – from building to architecture, from fine arts to urban landscape, from funerary art to modern 3D design – probably reaching its highest point in the eternal works of famous sculpturers, artists and architects such as Michelangelo, Donatello, Jacopo Della Quercia, Canova, Bernini, and many others. It is currently excavated in more than 100 quarries, processed almost everywhere and sold all over the world.

Abstract ‘Rosa Beta’ or ‘Sardinian Pink granite’, an Hercynian granitoid from the Italian island of Sardinia, is formally here nominated as a Global Heritage Stone Resource. Rosa Beta is sourced from the Gallura region of northern Sardinia and has been associated with human heritage since prehistoric times. Notably it can be found in construction ranging from prehistoric Tomba dei Giganti, the 1st century Pantheon in Rome and the Renaissance Cathedral in Pisa to early 20th century monuments in Brazil and Egypt. Most importantly, it has also been used very extensively in the late 20th century for significant construction in countries as wide ranging as the USA, Saudi Arabia, Hong Kong, Singapore and Australia.

Abstract The most frequently used material in Florentine Renaissance architecture was Pietra Serena, a sandstone that nowadays is found in a quite satisfactory state of conservation. The reason for this is that architects and stone cutters in the past made careful selections of the materials they employed. This conscientious picking out was very important because most sandstone layers have a composition that is not always suitable for assuring an acceptable durability. This paper deals with the mineralogical, chemical, petrographical and physical characteristics of the Pietra Serena sandstone quarried in the hills near Florence in order to verify what was affirmed by Vasari (1568) , Tuscan painter, architect and historian of art of the 16th century, and other Tuscan naturalists regarding the quality of this sandstone. As a matter of fact, analyses demonstrate that the Pietra Serena sandstones quarried in the hills of Settignano (to the northeast of Florence) and in the Gonfolina area (Lastra a Signa, to the west of Florence), are composed of layers particularly rich in calcite present mainly as sparitic cement. This calcitic cement gives great durability to the stone as is demonstrated by the good state of conservation of some Florentine monuments realized with Pietra Serena.

Abstract This paper reports the results of an Interreg Project (OSMATER – Sub-Alpine Observatory Materials Territory Restoration) that investigated the present and historical quarrying and processing activities in the cross-border area between the Ossola Valley (Italy) and the Canton Ticino (Switzerland), and the use of dimension stones in local and national architecture. These materials are in many ways unique for their abundance and lithological variety. In the past, their extraction, processing and application characterized in a decisive way the architectural and constructive culture, both in terms of prestigious architecture and civil buildings, establishing a relationship between ‘stones and culture’, and ‘territory and its resources’. In recent years, many traditions of the quarrying, processing and architectural activities are losing importance and interest is being loss, resulting in a loss of knowledge and historical memory. The loss of this knowledge is likely to become irreversible in the short term, with the disappearance of people and social groups as depositaries of tradition. We conclude that the creation of an ‘observatory’, like OSMATER, is desirable and, indeed, essential if we want to preserve the historical memory of the stone industry of an entire production area.

Abstract One of the peculiarities of Turin (NW Italy) lies on the presence of monumental arcades which mainly consist of stone material. These arcades, characterized by more than 12 km of interconnected paths, represent one of the widest city promenades of Europe and are an architectural, aesthetic and socio-economic example unique in the world. This paper, analysing the urban axis of Via Roma (Rome Street), aims to study the material used in arcade construction. The main stones occurring in Via Roma have been identified and described from a petrographic and mineralogical point of view in order to find out the corresponding geological units and original quarry sites. The minero-petrographic study is accompanied by an architectural survey that was performed applying different methods, as well as the geometric mapping and the perspective rectification of span-types, of block terminations and of other architectonical elements, in plan and in elevation, of the arcades. This allows us to emphasize the merging of cultural and scientific interest for the stone materials used in the historical architecture of a town closely interconnected to the surrounding Western Alps orogenic chain.

Abstract Podpeč Limestone is characterized by its dark grey or nearly black colour, contrasting with white fossil shells of the mollusc Lithiotis . This formation, which has been dated as Lower Jurassic, occurs in southern and southwestern Slovenia and is particularly conspicuous in areas SW of Ljubljana. The main quarry, which is not active, is located near the village of Podpeč near Ljubljana and has been recognized as a geological site of national importance; as such, it is officially protected as a natural monument. The utilization of Podpeč Limestone was first documented during the Roman period in Slovenia. At the end of the 5th century AD, with the decline of the Roman Empire, stone-cutting ceased at Podpeč for many centuries. Towards the end of the 19th century Podpeč Limestone became better-known. During the first half of the 20th century significant stonecutting workshops were established in Podpeč with most stone being supplied from the main quarry. The internationally renowned Slovenian architect Jože Plečnik (1872–1957) used Podpeč Limestone in various Slovenian buildings, some of national importance. The utilization and national recognition of Podpeč Limestone within Slovenia provide abundant support for its nomination as a Global Heritage Stone Resource.

Abstract The landscape of southeast Slovenia and its heritage in stone is, in terms of geology, primarily identified through the application of various types of sandstone of Miocene age, from those of Lower Miocene found in the wider areas of Celje and Ptuj to those of Middle Miocene found in and around Šmarje pri Jelšah and Rogaška Slatina. The inactive quarries in this region reveal traces of stonemasonry, while the outcrops of clastic sedimentary rocks reveal their diverse geological heritage. Hence, the wealth of natural and cultural heritage of a place is intertwined in one spot, offering an opportunity to make stonemasonry, stonemasons’ products, the traditional technological know-how, as well as arts and sciences, popular. With the stone heritage of southeast Slovenia gravely threatened, the abandoned quarries identified represent potential sites for obtaining natural stone for the purposes of renovating architectural heritage structures in the Slovenian countryside and more widely, like in the case of the revitalization of the abandoned quarry in Strtenica.