Global Heritage Stone Resource Research Articles

Petit Granit: A Belgian limestone used in heritage, construction and sculpture

Petit Granit is a Carboniferous grey-bluish crinoidal limestone that becomes shiny black when polished. The rock is known under several other names including Pierre bleue (Blue stone), but it should not be confused with other natural stones having a similar commercial name, which are superficially similar limestones. It consists of around 96% microcrystalline calcite and a high proportion of fossils, mainly crinoids. In addition some dolomite, quartz, pyrite, marcasite and fluorite are present. Around fifteen quarries are currently active, employing almost one thousand people and thus is an important part of the natural stone economy in Belgium. Petit Granit has an Appellation d'Origine Locale (Local Appellation of Origin) designation since 1999. It has been extracted in several regions of southern Belgium since the Middle Ages. The stone characterizes many facades of the urban architecture of Brussels and other Belgian cities, and since the second half of the 19 th century it has been used in various countries elsewhere in Europe and overseas. Its high density and uniformity mean that it takes an excellent polish and thus has versatile use as a dimension stone. Petit Granit has also been used widely in sculpture and architecture by several well known artists. However, deterioration has been observed when it has been used for exterior purposes, and appropriate measures need to be taken to prevent this. This stone can be considered as a possible candidate for Global Heritage Stone Resource nomination in Europe for its prominence and value both in construction and artistic uses.

Lede Stone: A potential “Global Heritage Stone Resource” from Belgium

Lede Stone is an important dimension stone with major relevance for Belgian and Dutch cultural heritage. It is sourced from the Eocene (Lutetian) Lede Formation, mainly in the region to the southeast of Ghent in Belgium. The oldest known use dates back to Roman times. With the rise of Gothic architecture during the middle ages, the use of Lede Stone increased substantially. Quarries arose at different locations at different times. Today only one active quarry remains, after a period of non-production during the 20th century. Current production is mainly used for restoration purposes. A major concern is the use of alien stones as a substitute for Lede Stone in cultural heritage restoration. In the light of the establishment of the Heritage Stone Task Group, this paper deals with requirements of its Terms of Reference and illustrates the stone's nature, technical properties, utilization and associated issues. It should contribute to the cultural appreciation and preservation of this stone.

ASSESSING PATHOLOGIES ON VILLAMAYOR STONE (SALAMANCA, SPAIN) BY TERRESTRIAL LASER SCANNER INTENSITY DATA

Abstract. This paper deals with the assessing of pathologies in façades using a variety of intensity data provided by different terrestrial laser scanner. In particular, a complex building built in the Villamayor Stone that is to be candidate as a Global Heritage Stone Resource has been chosen as study case. The Villamayor Stone were quarrying for the construction and ornamentation of monuments in Salamanca, declared World Heritage City by UNESCO in 1988. The objective of this paper is to assess the pathologies of Villamayor Stone and compare the results obtained through the laser techniques with the classical techniques of mapped pathologies (i.e. visual inspection). For that intensity data coming from laser scanners will be used as non-destructive techniques applied to the façades and several retired plaques (after of building restoration) of Villamayor Stone with pathologies (fissures, scales, loss of matter, humidity/biological colonization) carried to the laboratory. Subsequently it will perform different comparisons between the accuracy reached with the different sensors and a high precision model setup on laboratory which performs as “ground truth”. In particular, the following objectives will be pursued: i) accuracy assessment of the results obtained in in situ and laboratory; ii) an automation or semi-automation of the detection of pathologies in Villamayor Stone; iii) discriminate the different types of Villamayor Stone used in the façades in function of the radiometric response; iv) establish a methodology for detection and assessing of pathologies based on laser scanner intensity data applied to monuments and modern buildings built in Villamayor Stone.

Carrara Marble: a nomination for ‘Global Heritage Stone Resource’ from Italy

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.

About this title ‐ Global Heritage Stone: Towards International Recognition of Building and Ornamental Stones

This Geological Society Special Publication is dedicated to heritage stone: those natural stones that have special significance in human culture. Some stones that have had important uses in the past are now neglected because they are no longer extracted. Others are still commercially important, but their heritage uses have not been well documented in widely available sources. The Heritage Stone Task Group of the International Union of Geological Sciences is working to establish a new formal designation of 'Global Heritage Stone Resource' to recognize those stones that have had internationally significant architectural and ornamental uses. The aim is to spread awareness of the cultural heritage aspects of these stones, to help to encourage continued supply for maintenance and repair of important monuments and the preservation of historically important quarries. The aim is neither promote nor limit these stones for new construction: in some cases continuing commercial use might help to ensure future supplies for building conservation purposes.

The Kolmården serpentine marble in Sweden: a stone found both in castles and people's homes

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.

Villamayor Stone (Golden Stone) as a Global Heritage Stone Resource from Salamanca (NW of Spain)

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.

Colmenar Limestone, Madrid, Spain: considerations for its nomination as a Global Heritage Stone Resource due to its long term durability

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.

Global Heritage Stone: Estremoz Marbles, Portugal

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.

Natural stone in the built heritage of the interior of Brazil: the use of stone in Minas Gerais

Abstract The cultural heritage of Brazil built with natural stone is expressive and shows a great variety of rock types. The main differences between rock types are found when a comparison is made between the buildings located in the coastal zone and those located inland. In historical cities located on the coast, European limestones were widely used. Within the Brazilian interior, especially in the current State of Minas Gerais, a large number of historic buildings can be noticed. In this State, despite the large volumes of granites and gneisses and other less common rock types such as gabbros, basalts and sandstones, steatite and different types of schist, beside quartzites, were the rock types most commonly used in the construction of those 18th- and 19th-century buildings. This paper focuses on the extent and quality based on the use of steatites and schists in historic buildings in Brazil, which is part of a research project in progress. Assembled data justifies the inclusion of these rocks in the database on the rocks of world cultural heritage. The advancement of these studies may contribute to the maintenance and preservation of this heritage and the appropriate new uses of these rocks, as well as to propose some of them as Global Heritage Stone Resource for their international recognition.

‘Piedra Mar del Plata’: An Argentine orthoquartzite worthy of being considered as a ‘Global Heritage Stone Resource’

Abstract Although Argentina is a large country, only a few local stones meet the requirements to be used for construction purposes. Piedra Mar del Plata is a quartzite that has been used for more than 50 years, mainly as a building stone. During the 1930s and 1950s, its use in the construction of houses in the city of Mar del Plata (a famous beach resort) created a distinctive architectural style. Because of its durability and availability, the use of this stone rapidly spread to other parts of the country. Sculptures and monuments have also been made out of this stone. Mar del Plata architectural style is now part of the heritage of Argentina and represents the rise of the middle class, when local citizens could afford to build their own houses in a style different from the mansions, which were constructed by rich families with imported stone.

The Sierra Nevada serpentinites: the serpentinites most used in Spanish heritage buildings

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.

Podpeč limestone: a heritage stone from Slovenia

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.

Procedures and criteria for the definition of Global Heritage Stone Resources

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.

The ‘Global Heritage Stone Resource’ designation: past, present and future

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.

Piedra Pajarilla: a candidacy as a global heritage stone resource for Martinamor granite

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.

Rosa Beta granite (Sardinian Pink Granite): a heritage stone of international significance from Italy

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.

Portland Stone: A nomination for “Global Heritage Stone Resource” from the United Kingdom

Portland Stone, a well known ooidal limestone of Jurassic age from the United Kingdom is here nominated as a suitable Global Heritage Stone Resource. Portland Stone is considered to ideally fit the newly proposed designation as it has been utilised since Roman times in England and since the Middle Ages in the construction of major historic buildings including St Pauls Cathedral, British Museum and Bank of England in London. It was also the preferred building stone of Sir Christopher Wren, England's most famous architect. The international use of Portland Stone during the 20th century includes the United Nations building in New York City and the war graves of British and British Commonwealth soldiers. Portland Stone also continues to be quarried today in an environmentally sensitive manner whilst coastal outcrops of the material form a part of the Dorset and East Devon Coast World Heritage area (aka The Jurassic Heritage Coast).

Towards International Designation of a Heritage Dimension Stone

The Global Heritage Stone Resource (GHSR) designation has been proposed to recognise dimension stone types that have achieved important utilisation in human culture. Within internationally recognised rules, a GHSR will be determined on the basis of significant use in human history, wide geographic range of utilisation, and the benefits that would accrue from designation. Nominations will include a detailed description that allows professionals to introduce new scientific terminology, define geotechnical properties, identify the specific geographic/geological occurrence, and also the characteristic texture, colour and variability that contribute to aesthetic suitability for use. GHSR designation will have significant value for all professional groups that work with stone. The necessary GHSR delineation, including current and former quarry sources, will help to facilitate the safeguarding of resources for future use. Specific GHSR geotechnical characteristics associated with a formal name could also aid the development of specific geographical designations for stone, similar to those being currently applied in the European Union for foodstuffs. The international rules will provide a succinct pathway for GHSR designation with the assistance of a governing Board. A draft check list of essential GHSR properties has been prepared and tested using trial citations for “Portland Stone” and “Welsh Slate” from the United Kingdom.

Toward establishing a “Global Heritage Stone Resource” designation

Creation of the new international designation of Global Heritage Stone Resource is here advocated as a means of recognising those building stone resources that are widely represented in human culture. With introduction of the new designation, the profile of many natural stone materials will be raised to prominence through the researching of citations that will be necessary to create this new international standard. The proposed designation also offers a mechanism to formalise selected characteristics of natural stone material, not previously recognised, for example rock colour and traditional building stone names, in an internationally accepted context. The Global Heritage Stone Resource proposal also aims to complement and reinforce any existing geological standards that have been established especially those facilitated by IUGS, and its affiliated organisations. The interest and support of any geoscientists in advancing the Global Heritage Stone Resource proposal is sought.