The heritage unknown Brazilian marbles

Brazilian marble production and exports have grown in the last few years, following the trend of the international stone market to commercially exploit the uniqueness of natural stone as a competitive factor. Natural stone companies are spreading over the territory, in the country of exotic silicate rocks, searching for carbonate ones. It would seem that industrial marble production in Brazil is relatively new. Still, it started in the 19th century, achieving its heyday during the 20th century, followed by progressive decay as technology allowed the exploitation of abundant and more resistant granites. National marbles were used both in new constructions and in old buildings' reforms. Therefore, many heritage buildings in the country are dressed in ‘unknown’ or misidentified marbles. This work intends to give publicity to those materials, outlining the chronology of marble production in Brazil based on extensive bibliographic research and fieldwork. This story begins in the last quarter of the 19th century, when Brazil attracted many skilled European immigrants, primarily Italian, with knowledge of marble and technology, and several carbonate rocks had already been discovered in the country. The first mechanized marble quarries opened around 1870 in the state of Rio Grande do Sul to exploit Neoproterozoic whitish blueish marbles used in several monuments, such as the Conde Porto Alegre statue and, probably, the Municipal Palace, both in Porto Alegre city. Those quarries did not prosper due to the scarce infrastructure and skilled labour. The railway was the real booster for the Brazilian marble industry at the end of the century. As the railways expanded from the capital, new deposits were discovered, and already known others became profitable. That is the case of precambrian black, white and pink marbles of the Itupararanga quarries in São Paulo (ca 1895-1914)  used in the Municipal Theater. Also, the proximity to the railway allowed the success of the quarry, regarded as the first in the country, which opened in 1915 in Mar de Espanha, Minas Gerais. This compact white marble of the Juiz de Fora Complex (2,1 Ga) was called “National White Marble”, a name afterwards given to the one quarried in Italva (produced since 1933) and today to the white of Espírito Santo (produced since 1957). All those white marbles and the one from Paraná were used to build Brasília, the country’s capital. In Minas Gerais, too, in Lagoa Santa, important quarries of various coloured limestones and marbles supplied tiles and ornaments between 1925 and 1980 and cobblestone (still produced) for traditional Portuguese pavement to the whole country. Other representative marbles of that time are the 2,4 Ga Gandarella Formation beautiful red, white, bardiglio and mottled (oncolites) dolomitic marbles that ornament the Caraça Sanctuary and many buildings in Rio de Janeiro and other cities, as does the 2,1 Ga stromatolic meta-dolomite of Ouro Preto. Many other marble quarries opened from then on, being just a few active today (e.g. Santa Catarina, Paraná, Espírito Santo), but the industry movement towards marble quarrying could give adequate materials for heritage restoration.