UIA 2021 RIO: 27th World Congress of Architects Stones of Rio de Janeiro in its Built Heritage Nuria Fernández Castro Maria Heloísa Barros de Oliveira Frascá Centre for Mineral Technology – MCTIC MHB Serviços Geológicos Ltda. Kátia Leite Mansur Geology Dep./Fed. Univ. of Rio de Janeiro – UFRJ Abstract urban development, and the urgent need to This paper aims to bringing attention at the know and care for those stones to preserve necessity of interdisciplinarity of the cultural heritage. architectural and heritage conservation projects, specifically regarding the [...] we resolved, with the help of historical and current use of natural stones. science, a certain misunderstanding Despite of being long lasting building spread by some historians, that the materials, natural stones are affected by cloister had been made with sandstone alteration processes, naturally, as they are from Ilha da Boipeba [...] Well, who exposed to the environment and more has some rudiment of geology does not rapidly when in use, especially in urban see any sandstone in the cloister (except areas. Their degradation patterns and rate on the balcony sill) and even on Ilha da depend also on their mineralogical Boipeba there is no sandstone, as far as composition and geological history, which it is known! [...] we characterized the is the main object of study of geologists. limestone that was there and was a Being part of almost all the material dolomite. cultural heritage, the proper knowledge of —Mario Mendonça de the building stones, their characteristics Oliveira, Sobre Pedra, Arquitetura & and source is fundamental to the success of Restauro, p.26 conservation interventions and should be documented. Nevertheless, the lack of documentation on stones of the built Introduction heritage is a common issue around the Stones have accompanied the development of world. To address this problem and raise almost all societies. Due to their local awareness of the importance of natural availability, beauty, and durability they have stones characterization and been used along human history as utensils, artworks, infrastructure works, paving, urban documentation, the Heritage Stones ornaments, building materials, etc. In other Subcomission, of the International Union words, stones are witnesses of the social and of Geological Sciences, established the cultural development of humankind. Their Global Heritage Stone Resource durability is stated by the enormous quantity of designation for stones significant to the remains of old civilizations all over the world, human culture. Most of the designated especially in Asian and European countries. The stones so far are from European countries, monumental architectural site of Gobekli Teppe, but in Brazil, particularly in Rio de in Turkey, for example, believed to be a place Janeiro, there are stones whose significance for cult and rituals, has monolithic limestone deserve to be internationally recognized. sculptures which have survived 11,000 years This paper shows an overview of the most [1]. The undeniable beauty of natural stones is important stones of Rio de Janeiro, their represented all over the world by sculptures, widespread use, their relationship with the ornaments, old and contemporary floorings and landscape of the city and its social and coverings, such as the book match on Fig. 1. 520 PAPERS: VOLUME I of III UIA 2021 RIO: 27th World Congress of Architects Figure 1. Bookmatch of the Botanic Wave (natural quartzite, approximate dimensions: 6 m x 4 m). Photo: Pettrus Mineração, Brazil (2020). Their local availability has given us beautiful stone has its own. The stones we use and see cities built on local stones as the Villamayor have passed by many long-lasting Sandstone of Salamanca (Spain) or the Marble transformations (of millions of years). The of Carrara (Italy), though there are many other action of pressure, temperature, fluids, and examples around the world. Stones are the many other factors, in a very specific physical support and memory of human culture underground environment (that can be several in architectural and artistic works and to kilometers below the Earth's surface), preserve this memory for the future generations, determined the formation of the different they must be properly valued and treated, minerals that constitute each specific rock. meaning properly known. Today, more than 150 Once the rocks are exposed to the surface and its million tons of natural stones are produced environmental agents, they will be slowly yearly in the world, mostly to be used for altered: physical, chemical, and mineralogical flooring and covering. One third of that quantity changes occur, naturally. is traded in the international market [2] Those changes are accelerated when the rocks competing with a wide range of other building are quarried, transported, shaped to be building materials (ceramics, wood, glass, artificial stones, and employed in a built environment. stones, cement-based products and so forth). This occurs particularly in urban areas where Although the selection and specification of a they are exposed to other physical, chemical, stone is usually based on its aesthetic features, it and biological agents that interact with the should be improved by considering its natural stones starting new alteration processes. characteristics, composition, texture (i.e., its Consequently, to better use, maintain, and mineral arrangement), and alteration degree [3]. conserve architectural works in stone, the It is especially important for the Built Heritage intimate knowledge of this natural building Conservation as many examples of unsuccessful material is essential. interventions in historical buildings demonstrate Unfortunately, it seems that this is not what has [4]. happened throughout history. The conservation of the built heritage faces the added difficulty of Natural Stones the lack of documentation of the stones used, Stones are natural resources, so their aesthetic their properties, and their source of origin, as and mechanical/technological characteristics occurred regarding the white marbles that were are the result of a unique geological history that used in Brasília [5]. goes back to many million years ago and each PAPERS: VOLUME I of III 521 UIA 2021 RIO: 27th World Congress of Architects Also, the involvement of geologists, the sustainable use of natural stones worldwide professionals that are familiar with natural and it could yield many social benefits through: stones, is not a usual practice among • Increasing awareness of natural stone and its conservation interventions. Geologists would be positive attributes in terms of sustainability assets when choosing the most appropriate and regional economic development. treatments or replacement materials in order to • Facilitating the preservation/restoration of prevent future damages, which would be existent stone heritage by using appropriate fundamental to the intervention success. materials. To address this issue, the Heritage Stones • Encouraging the safeguard of important Subcomission (HSS) of the International Union heritage stone resources from subsequent of Geological Sciences (IUGS), elaborated a sterilization when there is pressure for geological standard, the Global Heritage Stone alternative development. Resource - GHSR designation, for building and • Promoting the appropriate specification of ornamental stones that have been significant in stone in the same way that regional human culture. It gives the designated stones an designation of foodstuffs has occurred in the international recognition that helps increase European Union. professionals and community awareness of From the list of stone recognized as GHSR, few natural stones in the cultural heritage. It also of them, though, are from emerging countries. enhances international co-operation for the For those countries, the recognition of building research and documentation of natural stone stones as GHSR can be an empowering tool for resources. The GHSR tittle provides visibility to people in need of scientific knowledge. It would such an important Earth’s resource, present in encourage them to take ownership of their almost all the heritage buildings and cultural heritage and, consequently, support its monuments. Their conservation is closely conservation. related to the knowledge of the stone nature, It can also enhance the social and scientific geological frame, sources, production history, values of architectural works and generate behavior within the environment, and economic resources through scientific tourism. conservation practices [6]. Additionally, expanding knowledge about natural stones could improve their use and Global Heritage Stone Resource maintenance. Twenty two stones have been recognized as Since the Brazilian built heritage is mostly less GHSR so far: Portland stone (UK), Petit Granite than 500 years old, it has not been properly (Belgium), Larvikite (Norway), Podpêc valued for its historical and cultural importance. Limestone (Slovenia), Hallandia Gneiss The lack of documentation, especially regarding (Sweden), Carrara Marble (Italy), Villamayor its building stones, is a common issue that needs Sandstone (Spain), Estremoz Marble (Portugal), to be addressed to avoid inadequate Maltese Globigerina Limestone (Malta), conservation practices. These improper Jacobsville Sandstone (USA), Lede Stone practices could lead to a loss of heritage objects (Belgium), Welsh Slate (Wales), Piedra Mar del of great importance, which, within the Brazilian Plata (Argentina),