Rio Grande do Sul State presents varied geological characteristics, and rocks that record much of the history of the planet, with ages ranging from around 2 billion to 500 million years, grouped in the so-called Sul-Rio-Grandense Shield, which is the area with the largest presence of mineral occurrences of economic relevance.Sedimentary rocks of Carboniferous and Triassic (300-200 million years) are deposited in the Peripheral Depression. Such rocks formed the main coal deposits of the State. In the basaltic plateau, result of fissure lava flows occurred in the Cretaceous, mineral wealth is not so large, except in the areas where gems such as amethysts and agates are present. In the coastal region, younger sediments settled, forming the Coastal Plain.
The State is producer and exporter of precious stones, with emphasis to amethyst and agate, that have superior gemological quality and high international acceptance. It is also a producer and exporter of ornamental rocks (granites and marbles), which have had their demand increased. The production of ornamental rocks is concentrated in center-south of the State. Although mineral coal is the main product, with total resources of about 28 billion tons, which correspond to 89% of the country's coal resources.
Along with Santa Catarina, Rio Grande do Sul is the largest producer of mineral coal in Brazil, and the state processed production in 2014 was of approximately 5 million tons. Candiota deposit alone has 38% of all the national coal. At present, the biggest prospects for the use of mineral coal are in thermoelectric generation in the industrial application for heat generation (thermal energy) for metallurgical use. In Campanha region, where the largest deposits are located, researches conducted for the use of clay that occurs along these deposits showed great potential for economic use for ceramics manufacturing.
Source: DNPM. Anuário Mineral Estadual 2015 - ano base 2014
¹Value of production sold, consumed or transferred for industrialization.
²The commercialized production of mineral water covers both bottled products and the volumes used in the composition of industrialized products. In 2014, 83.26% of the commercialized volume of mineral water in Rio Grande do Sul corresponded to bottled products.