Brazili

Regional Level Types
Brazil	Country

This page is currently not sponsored. Click here to sponsor this page.

PhotosMapsSearchMineralogy

Brazil is the largest country in South America, and the fifth-largest country in the world, at about 8.5 million square kilometers. That compares to 8.1 million square kilometers for the lower 48 states in the United States and 9.8 million total for the U.S. The population of Brazil in 2016 was 206.7 million, compared to 323.1 million for the U.S. Brazil includes 26 states plus a Federal District (Figure 1). Brazilian states are divided into municipalities–roughly equivalent to counties in the U.S.



Brazil includes only modest topographic features, with the highest points of land somewhat in excess of 1500 meters. Prominent mountains are lacking, but locally the hills are deeply dissected and may be quite rugged. Much of the terrain is covered by savanna vegetation. The savanna grades into rainforests in the Amazon Basin (north-westward), and into tropical, semi-deciduous forests where the terrain is influenced by its proximity to the Atlantic Ocean (generally eastward and southward). Much of the northeastern portion of the country has a semi-arid climate with thorny scrub vegetation.

Brazil has the second-largest economy in the Western Hemisphere, second only to the United States. Worldwide, Brazil ranks sixth in overall mining production. In 2011 there were 8870 mining companies operating in Brazil, employing about 175,000 workers (Brazilian Mining Association, 2012). In recent years, Brazil has led the world in niobium production, accounting for 98% of the world’s total. As of 2010, Brazil was the world’s second-largest producer (and largest exporter) of iron ore. Brazil is also third in bauxite production, fifth in manganese and tin, seventh in nickel, eighth in aluminum, twelfth in uranium, and thirteenth in gold (Soutter, 2012; Gurmendi, 2015).

About two-thirds of Brazil is underlain by Precambrian rocks (Figure 2), including ancient cratonic (long stable) regions and orogenic (“mobile”) belts that were active largely from about two billion years ago through the end of the Precambrian and extending into the earliest Paleozoic. The richest iron, tin, and nickel deposits formed in Archean and Paleoproterozoic rocks, as did much of the gold and platinoid metals found in placer deposits.


Orogenic belts formed by the convergence of crustal plates, largely in the Mesoproterozoic and Neoproterozoic. Most pegmatitic granites that yield colored gemstones formed in the Neoproterozoic to the earliest Paleozoic (1,000-541 million years ago), as did more metallic ores including gold and Mississippi Valley-type lead-zinc deposits. Many of the diamond-bearing kimberlites and related rock types were intruded during the Cretaceous Period. Amethyst, agate, and opal-bearing volcanic rocks were also deposited in the Cretaceous. Bauxite (aluminum) and manganese deposits formed during the Cenozoic by intense tropical weathering that continues today. Cenozoic weathering also produced extensive secondary deposits of iron, nickel, phosphate, and even gold. Sites of industrial minerals' production are shown in Figure 3.


In 2005 Brazil was ranked first in the world in the variety and quantity of gemstones produced (Baretto and Bittar, 2010), and continues to be pre-eminent today (see Figure 4). Brazil once led the world in diamond production, but has steadily slipped in world ranking since kimberlite deposits were discovered (1869) in other places, falling to less than 1% today; most of Brazil’s diamonds have been recovered from placer deposits. Production of colored gemstones has increased dramatically during the latter half of the 20th century, and Brazil is now the world’s leading producer of amethyst, citrine, and topaz, and produces a major portion of the aquamarine, tourmaline, chrysoberyl (alexandrite and cat's-eye), emerald, garnet, and opal (e.g., Baretto and Bittar, 2010).



In 2012, approximately 61% of diamonds and gemstones were mined by individuals and small independent operators ("garimpeiros"); major mining companies produced 39%. Deposits of both diamonds and colored gemstones exploited by garimpeiros tend to be localized and very small, requiring time-consuming techniques of extraction, and both factors have discouraged larger companies from pursuing them. The predominance of small-scale operations has tended to keep garimpeiros and their workings out of the public eye and hidden from government monitoring. Historically, tax burdens for mineral extraction and sale were very high (at one time as high as 53%), contributing to a culture of "underground" activities (i.e., outside legal registration and reporting). Therefore, the true value of gemstone production has been difficult to quantify. The official production of gemstones in 2005 amounted to US$47 million, whereas the export of gemstones in that year was US$135 million (Baretto and Bittar, 2010). Thus, much of the actual production seems to have gone unreported. In recent years, lower tax rates have helped this situation. Other functions involved in the chain of gemstone production include cutting and polishing, trade, and export. The entire gemstone industry in Brazil, from mining to export, was estimated to employ 350,000 workers in 2006 (Baretto and Bittar, 2010). Officially, the state of Minas Gerais accounts for 74% of colored gemstone production in Brazil. Four other states, including Bahia, Rio Grande do Sul, Matto Grosso, and Goiás (states labeled in Figure 1) are also big producers, with all five of those states accounting for 97% of Brazil's total production in 2005 (Barreto and Bittar, 2010).

As of late 2017, there were 771 different minerals reported from Brazil, and 72 minerals have their type localities in Brazil (data from Mindat website). The distribution of mineral wealth is skewed toward certain states. State size, geological history, transportation to and within them, and degree of cover by vegetation and surficial deposits including soils and other loose materials, all play a role in the number of minerals reported from each state (see Table 1 below). Note that Minas Gerais leads the second most prolific state, Bahia, by a more than two-to-one margin. Details of the geology and mineralogy at the state, regional, and district levels, as well as for more precise descriptions down to the level of specific localities, have been added on many of the Mindat locality pages.