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57-492: The municipality became one of the most populous cities of Latin America, counting on about 40,000 people in 1730 and, decades after, 80,000. At that time, the population of New York was less than half of that number of inhabitants and the population of São Paulo did not surpass 8,000. Officially, 800 tons of gold were sent to Portugal in the eighteenth century, not to mention what was circulated in an illegal manner, nor what remained in

114-544: A subtropical highland climate ( Cwb , according to the Köppen climate classification ), with warm and humid summers and mild, dry winters. Frost is occasional and occur in June and July. There is a report of snow in the city in the year of 1843. Although Ouro Preto now relies heavily on the tourism industry for part of its economy, there are important metallurgic and mining industries located in town, such as Novelis, formerly Alcan,

171-812: A city, receiving the title of "National Historic Heritage" from the National Institute of Historic and Artistic Heritage . With the arrival of Juscelino Kubitschek to the state government and later to the Presidency of the Republic , many improvements were made in Diamantina, such as the foundation of the Federal School of Dentistry of Diamantina, the Hotel Tijuco, the Júlia Kubitschek State School and

228-542: A cold or fever. In Europe during the Middle Ages, topaz was believed to enhance mental powers. In India, people believed topaz granted beauty, intelligence, and longevity when worn over the heart. Topaz is a gemstone . In cut and polished form, it is used to make jewelry or other adornments. Lower quality topaz is commonly used as an abrasive material due to its hardness and it is used to produce refractory materials for high temperature environments. Topaz can be used as

285-406: A common souvenir among tourists, and can be found in many shops in the city's town centre and street fairs. Jewelry made of local precious and semi-precious gemstones (such as hematite) can also be found for sale. Ouro Preto is also a university town with an intense student life. The Universidade Federal de Ouro Preto (Federal University of Ouro Preto or UFOP) has approximately 10,000 students in

342-466: A flux in steel production. Using topaz as a refectory material does have some health and environmental concerns due to the production of fluorine as a byproduct of calcining topaz. Topaz is a part of the second rank of gemstones, or semiprecious stones, accompanying aquamarine , morganite , and tourmaline . The first rank of gemstones, or precious stones, includes ruby , sapphire , diamond , and emerald . Orange topaz, also known as precious topaz,

399-461: A gold-bearing stream was discovered in Itacolomi, which would be renamed Gualacho do Sul. In 1711, several small settlements were united as a municipality called Villa Rica, which later came to be called Ouro Preto. This name was adopted on 20 May 1823, when the former Vila Rica was elevated from village to city. The name "Black Gold" comes from the gold covered with a layer of iron oxide that is found in

456-483: A large component of mining operations, is drawn away from neighboring communities to create a lack of water. Tailings leftover from the mining process can leach contaminants into nearby water systems and can contaminate the drinking water of local communities. Some ways humans can be impacted by gem mining is through danger in mines and inadequate compensation. Accidents such as collapsing mines and machinery malfunctioning can put human life in danger. Those working in

513-729: A more recent gem, weighed 22,892.5 carats (4,578.50 g). Large, vivid blue topaz specimens from the St. Anns mine in Zimbabwe were found in the late 1980s. Colorless and light-blue varieties of topaz are found in Precambrian granite in Mason County, Texas within the Llano Uplift . There is no commercial mining of topaz in that area. It is possible to synthesize topaz. Large-scale topaz mining typically uses open pit and underground mining to extract

570-512: A population similar to that of the prosperous São João del-Rei . In the 18th century it grew due to the large local production of diamonds, which were exploited by the Portuguese crown. It was initially known as Arraial do Tejuco (or Tijuco) (from the Tupi tyîuka, "rotten water"), Tejuco and Ybyty'ro'y (Tupi word meaning "cold mountain", by the junction of ybytyra ("mountain").) and ro'y ("cold"). During

627-598: A sample of topaz. After heating, the topaz lost mass, and through examination Brewster concluded Topaz was formed in a wet environment creating these liquid-filled cavities. This liquid is a hydrocarbon with a refractive index of 1·13. Topaz's crystal habit takes many forms. It can display a range of slender and long crystals to bulky and short. There can also be variation in the terminations displaying blunt, pyramidal, chisel, or wedge-shaped terminations. The perfect cleavage {001} in topaz breaks no Si-O bonds within its structure and only breaks Al-O and Al-F bonds. This cleavage

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684-526: A sparkling table facet surrounded by dead-looking crown facets or a ring of sparkling crown facets with a dull well-like table. It also takes an exceptionally fine polish, and can sometimes be distinguished from citrine by its slippery feel alone (quartz cannot be polished to this level of smoothness). Another method of distinguishing topaz from quartz is by placing the unset stone in a solution of bromoform or methylene iodide . Quartz will invariably float in these solutions, whereas topaz will sink. Topaz

741-425: A tendency to break along such a cleavage plane if struck with sufficient force. Topaz has a relatively low index of refraction for a gemstone, and so stones with large facets or tables do not sparkle as readily as stones cut from minerals with higher refractive indices, though quality colorless topaz sparkles and shows more "life" than similarly cut quartz. When given a typical "brilliant" cut, topaz may either show

798-458: A threat of landslides . The pollution produced by mining can impact the environment around it and damage its health. Deforestation undergone to create the mine, along with the machinery used during the mining process, adds greenhouse gasses to the atmosphere. Deforestation also removes habitats and biodiversity from a large area of natural space. These disruptions to the ecosystem can be challenging to wildlife and local populations. Water, also

855-499: Is twinned with: Diamantina also cooperates with Třeboň in the Czech Republic. Topaz Topaz is a silicate mineral made of aluminum and fluorine with the chemical formula Al 2 Si O 4 ( F , OH ) 2 . It is used as a gemstone in jewelry and other adornments. Common topaz in its natural state is colorless, though trace element impurities can make it pale blue or golden brown to yellow-orange. Topaz

912-469: Is 7,348 km and in 2006 the population was 80,063 inhabitants. The population density (2000) was 11.2 inhabitants/km . Before the arrival of Portuguese settlers, in the 16th century (the first reports give account of expeditions that went up the Jequitinhonha and São Francisco Rivers), Diamantina, like the entire region of the current state of Minas Gerais, was occupied by indigenous peoples of

969-435: Is Brazil's sixth largest industry. Diamantina, Minas Gerais Diamantina ( Portuguese pronunciation: [dʒiamɐ̃ˈtʃinɐ] ) is a Brazilian municipality in the state of Minas Gerais . Its estimated population in 2020 was 47,825 in a total area of 3,870 km . Arraial do Tijuco (as Diamantina was first called) was built during the colonial era in the early 18th century. As its name suggests, Diamantina

1026-497: Is a major tourist destination, for its well-preserved colonial appearance with baroque architecture and cobblestone streets. The city contains numerous churches, many known for their religious art and baroque architecture. Some of the best known are: A number of former gold mines in the city offer tours to tourists. One of the most well known is the Mina do Chico Rei, near the sanctuary of Nossa Senhora da Conceição. Another infamous mine

1083-520: Is commonly associated with silicic igneous rocks of the granite and rhyolite type. It typically crystallizes in granitic pegmatites or in vapor cavities in rhyolite lava flows including those at Topaz Mountain in western Utah and Chivinar in South America. It can be found with fluorite and cassiterite in various areas including the Ural and Ilmensky mountains of Russia, Afghanistan, Sri Lanka,

1140-634: Is considerably heavier than citrine (about 25% per volume) and this difference in weight can be used to distinguish two stones of equal volume. Also, if the volume of a given stone can be determined, its weight if it were topaz can be established and then checked with a sensitive scale. Likewise, glass stones are also much lighter than equally sized topaz. A variety of impurities and treatments may make topaz wine red, pale gray, reddish-orange, pale green, or pink (rare), and opaque to translucent/transparent. The pink and red varieties come from chromium replacing aluminium in its crystalline structure. Imperial topaz

1197-450: Is diagnostic for this mineral. The 2V optical angle in topaz can range from 48° to 69.5°. Low fluorine content yields a smaller angle and high fluorine content yields a larger angle. Topaz in its natural state is colorless, often with a greyish cast. It also occurs as a golden brown to yellow color which makes it sometimes confused with citrine , a less valuable gemstone. The specific gravity of all shades of topaz, however, means that it

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1254-446: Is formed. Another method uses a combination of amorphous Al 2 O 3 , Na 2 SiF 6 , and water which is heated to a temperature of 500 °C, put under a pressure of 4000 bars, and left for 9 days. To care for a topaz gemstone, it is best to avoid ultrasonic cleaners or steam as this could produce small fractures within the crystal. Warm water with soap is the best way to wash it. To choose an ethically sourced topaz gemstone, it

1311-587: Is heat treated and irradiated to produce a more desired darker blue. Mystic topaz is a colorless topaz that has been artificially coated via a vapor deposition process giving it a rainbow effect on its surface. Although very hard, topaz must be treated with greater care than some other minerals of similar hardness (such as corundum ) because of a weakness of atomic bonding of the stone's molecules along one or another axial plane (whereas diamonds, for example, are composed of carbon atoms bonded to each other with equal strength along all of its planes). This gives topaz

1368-424: Is likely not meant here. An English superstition also held that topaz cured lunacy . The ancient Romans believed that topaz provided protection from danger while traveling. During the Middle Ages, it was believed that attaching the topaz to the left arm protected the owner from any curse and warded off the evil eye . It was also believed that wearing topaz increased body heat, which would enable people to relieve

1425-410: Is often treated with heat or radiation to make it a deep blue, reddish-orange, pale green, pink, or purple. Topaz is a nesosilicate mineral , and more specifically, an aluminosilicate mineral. It is one of the hardest naturally occurring minerals and has a relatively low index of refraction . It has the orthorhombic crystal system and a dipyramidial crystal class . It occurs in many places in

1482-439: Is recommended to search for a stone that the seller knows the origin of. If the seller cannot produce information about the locality and mine that the topaz was collected from, it is likely that it was collected unethically. Topaz is an accessory mineral to felsic igneous, sedimentary, and hydrothermally altered rocks. The crystal structure of topaz alternates between sheets of (F, OH) 2 O and O along (010) with Al occupying

1539-503: Is the birthstone for the month of November, the symbol of friendship, and the state gemstone of the U.S. state of Utah . Blue topaz is the state gemstone of the US state of Texas . The 4th wedding anniversary gem is blue topaz and the 23rd is imperial topaz. Synthetic topaz can be produced using a method that includes the thermal hydrolysis of SiO 2 and AlF 3 . When these compounds are heated to temperatures of 750° to 850 °C topaz

1596-552: Is the Mina da passagem. In the early 19th century, Portugal gave the United Kingdom exclusive use of this mine for 100 years to pay Portugal's sovereign debts. This is the world's largest mine open to the public. The municipality contains about 10% of the 31,270 hectares (77,300 acres) Serra do Gandarela National Park , created in 2014. The street carnival in Ouro Preto attracts thousands of people every year. Carnival blocks are

1653-457: Is yellow, pink (rare, if natural), or pink-orange. Brazilian imperial topaz can often have a bright yellow to deep golden brown hue, sometimes even violet. Many brown or pale topazes are treated to make them bright yellow, gold, pink, or violet colored. Some imperial topaz stones can fade from exposure to sunlight for an extended period of time. Naturally occurring blue topaz is quite rare. Typically, colorless, gray, or pale yellow and blue material

1710-556: The Captaincy , in 1729, the then D. Lourenço de Almeida. Portugal's response was to impose full control over the diamond regions of Minas Gerais. In 1734, the Intendency of Diamonds was created, whose regime was totally controlling and authoritarian. The Portuguese Crown's monopoly over diamond deposits lasted until 1845. Diamantina emancipated itself from the municipality of Serro only in 1831, changing its name to Diamantina because of

1767-561: The Macro-Jê languages . Diamantina was founded as Arraial do Tejuco in 1713, with the construction of a chapel that honored the patron Saint Anthony of Padua . The locality had strong growth when the Diamonds were discovered in 1729. At the end of the 18th century, it was the third largest population in the Captaincy General of Minas, behind the capital Vila Rica, today Ouro Preto , and with

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1824-669: The Middle Ages , the name topaz was used to refer to any yellow gemstone, but in modern times it denotes only the silicate described above. Many English translations of the Bible , including the King James Version , mention topaz. However, because these translations as topaz all derive from the Septuagint translation topazi[os] , which referred to a yellow stone that was not topaz, but probably chrysolite ( chrysoberyl or peridot ), topaz

1881-444: The freshmen , also known as "bixos" (misspelling of "bichos", Portuguese for "animals"), have to undergo a hazing period, called batalha (battle), before being accepted permanently as residents of the houses. The final choice of the freshmen, called escolha , has to be unanimous among the senior students of the house. The Museu Mineralógico da Escola de Minas (Mineralogy Museum) can be of special interest to visitors. It belongs to

1938-524: The 18th century, the city was famous for having sheltered Chica da Silva , a freed slave who was the wife of the richest man in Colonial Brazil , João Fernandes de Oliveira. Diamantina represented the largest mining of diamonds in the western world in the 18th century, and for nine years, the Portuguese Crown was not aware of the discovery of diamonds in the region, which was done by the governor of

1995-659: The Czech Republic, Germany, Norway, Pakistan, Italy, Sweden, Japan, Brazil, Mexico; Flinders Island , Australia; Nigeria and the United States. Topaz was found around the time of the 1700s in a pegmatite formation within the central Urals Mountains in Russia. Brazil is one of the largest producers of topaz, some clear topaz crystals from Brazilian pegmatites can reach boulder size and weigh hundreds of pounds. The Topaz of Aurangzeb , observed by Jean Baptiste Tavernier weighed 157.75 carats (31.550 g). The American Golden Topaz ,

2052-560: The Diamantina Sports Square. In 1999, it was elevated to the category of "heritage of humanity" by the United Nations Educational, Scientific and Cultural Organization . Diamantina is located 292 kilometers almost directly north of the state capital, Belo Horizonte , in a mountainous area. The elevation of the municipal seat is 1,114 meters. The Jequitinhonha River , one of Brazil's most important rivers, flows to

2109-542: The UFOP's School of Mining, which opened its doors on 12 October 1876. The museum is located at the Tiradentes Square No. 20, in the town's historical center, and contains a rich assortment of minerals on display, including precious and semi-precious gemstones and large crystals . Security is tight, however (for example, no cameras are allowed), due to the incalculable value of the gemstones and ores on display. Ouro Preto

2166-564: The birthplace of the Inconfidência Mineira , a failed attempt to gain independence from Portugal . The leading figure, Joaquim José da Silva Xavier , known as Tiradentes, was hanged as a threat to any future revolutionaries. In 1876, the Escola de Minas (Mines School) was created. This school established the technological foundation for several of the mineral discoveries in Brazil. Ouro Preto

2223-419: The city. The city centre contains well-preserved Portuguese colonial architecture, with few signs of modern urban development. New construction must keep with the city's historical aesthetic. 18th- and 19th-century churches decorated with gold and the sculptured works of Aleijadinho make Ouro Preto a tourist destination. The tremendous wealth from gold mining in the 18th century created a city which attracted

2280-464: The city. Many of them live in communal houses that are somewhat similar to fraternity houses as found in North American colleges. These communal or shared houses are called repúblicas , 66 of which are owned by the university, called repúblicas federais , and 250 are privately owned ( repúblicas particulares ). The repúblicas system of Ouro Preto is unique in Brazil. No other university city in

2337-506: The colony, such as gold used in the ornamentation of the churches. Other historical cities in Minas Gerais are São João del-Rei , Diamantina , Mariana , Tiradentes , Congonhas and Sabará . Founded at the end of the 17th century, Ouro Preto (meaning Black Gold ) was originally called Vila Rica, or "Rich Village", the focal point of the gold rush and Brazil's golden age in the 18th century under Portuguese rule. Between 1695 and 1696,

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2394-479: The country has exactly the same characteristics of the student lodgings found there. It shares traits with the repúblicas of the Portuguese University of Coimbra , where the tradition originated. Before universities were founded in Brazil, Coimbra was where most of the rich students who could afford an overseas education went to. Each república has its own different history. There are repúblicas in which

2451-569: The early Egyptians ( Topapwene ) – "land of the Topaz". Pliny said that Topazos is a legendary island in the Red Sea and the mineral "topaz" was first mined there. Alternatively, the word topaz may be related to the Sanskrit word तपस् "tapas", meaning "heat" or "fire". Nicols, the author of one of the first systematic treatises on minerals and gemstones, dedicated two chapters to the topic in 1652. In

2508-746: The east of the municipal seat. Diamantina is linked to the state capital by federal highway BR-259 , by way of Curvelo . Diamantina Airport has regular flights to Belo Horizonte. The municipality contains the 16,999 hectares (42,010 acres) Biribiri State Park , created in 1998, which contains the historic village of Biribiri. Neighboring municipalities are: Olhos d'Água and Bocaiúva (N); Carbonita , Senador Modestino Gonçalves , São Gonçalo do Rio Preto , and Couto de Magalhaes de Minas (E); Santo Antônio do Itambé , Datas , Serro and Monjolos (S); Augusto de Lima , Buenópolis , and Engenheiro Navarro (W). The main economic activities are tourism, services, small industry and agriculture. The GDP in 2005

2565-533: The gem and treating it to achieve the desired color. Mining for topaz can cause some environmental concerns mostly associated with larger-scale operations. The introduction of a large open pit mine into an environment leads to modification of the land around it to make it accessible to workers. After use of such mines is over, they are often refilled with loose sediments left over from the mining process. These loose sediments can be washed away to other areas, cutting off water features, destroying farmland, and creating

2622-457: The gem. The waste material is discarded using large machines to transport it away while the valuable ore is washed and sorted to recover the topaz gems. In smaller-scale mines, dry sieving is used in alluvial environments by shoveling the material into sieves to separate the gems from unwanted dust and debris. The topaz can then be selected by hand from the remaining material. Mined topaz is then sent to be processed for use in jewelry by polishing

2679-434: The intelligentsia of Europe. Philosophy and art flourished, and evidence of a baroque revival called the "Barroco Mineiro" is illustrated in architecture as well as by sculptors such as Aleijadinho, painters such as Manoel da Costa Ataíde , composers such as Lobo de Mesquita , and poets such as Tomás António Gonzaga . At that time, Vila Rica was the largest city in Brazil, with 100,000 inhabitants. In 1789, Ouro Preto became

2736-577: The large volume of diamonds found in the region. The delay was due to the need for greater local control by the colonial authorities, since in the mid-18th century the population was larger than that of Vila do Príncipe do Serro Frio, head of the region. Life in Diamantina at the end of the 19th century was portrayed by Alice Brant in her book Minha Vida de Menina , which became a landmark in Brazilian literature after being rediscovered by Elizabeth Bishop . In 1938, Diamantina celebrated its 100th anniversary as

2793-446: The most important aluminum factory in the country, Vale S.A. , and others. Main economic activities are tourism, transformation industries, and mineral riches such as deposits of iron , bauxite , manganese , talc and marble . Minerals of note in the city are: gold , hematite , dolomite , tourmaline , pyrite , muscovite , topaz and imperial topaz, which is a stone only found in Ouro Preto. Soapstone handicraft items are

2850-484: The most traditional type of parade, where bands play across the town, followed by herds of paraders dressed up in costumes. The block Zé Pereira dos Lacaios , founded in 1867, is the oldest block that is still active in Brazil. Parades with samba schools also happen. The street party is also celebrated in neighbouring towns such as Mariana. Ouro Preto was a setting in the comedy movie Moon over Parador (1988), with actors Richard Dreyfuss and Sonia Braga . Mining

2907-403: The octahedral sites and Si in the tetrahedral sites. Fluorine can be substituted by hydroxide in topaz by up to 30 mol.% in nature and hydroxide-dominating topaz can be made in laboratories but has not been found in nature. On occasion, cavities can be found within topaz and they are filled with a liquid called brewsterlinite. Brewsterlinite was discovered by David Brewster upon heating

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2964-446: The world. Some of the most popular places where topaz is sourced are Brazil and Russia. Topaz is often mined in open pit or alluvial settings. The word "topaz" is usually believed to be derived (via Old French : Topace and Latin : Topazius) from the Greek Τοπάζιος (Topázios) or Τοπάζιον (Topázion), from Τοπαζος. This is the ancient name of St. John's Island in the Red Sea which

3021-825: Was Poços de Caldas with 0.841, while the lowest was Setubinha with 0.568. Nationally the highest was São Caetano do Sul in São Paulo with 0.919, while the lowest was Setubinha. In more recent statistics (considering 5,507 municipalities) Manari in the state of Pernambuco has the lowest rating in the country—0,467—putting it in last place. There were 2 hospitals and 31 health clinics in 2005. Educational needs were met by 30 primary schools and 9 middle schools. There were 3 institutions of higher learning: Faculdade de Ciências Jurídicas de Diamantina - FCJ (a law school), Faculdade de Filosofia e Letras de Diamantina - FAFIDIA (humanities), and Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM (federal public). Diamantina

3078-417: Was R$ 184 million, with 140 million coming from services, 23 million from industry, and 8 million from agriculture. In 2006 there were 1,248 rural producers on 73,000 hectares of land. Only 24 of the establishments had tractors. There were 14,000 head of cattle. The social indicators rank Diamantina in the top tier of municipalities in the state. The highest ranking municipality in Minas Gerais in 2000

3135-593: Was a center of diamond mining in the 18th and 19th centuries. A well-preserved example of Brazilian Baroque architecture , Diamantina is a UNESCO World Heritage Site . Other historical cities in Minas Gerais are Ouro Preto , São João del-Rei , Mariana , Tiradentes , Congonhas and Sabará . Diamantina is a statistical micro-region that includes the following municipalities: Diamantina, Datas , Felício dos Santos , Gouveia , Presidente Kubitschek , São Gonçalo do Rio Preto , Senador Modestino Gonçalves , and Couto de Magalhães de Minas . The area of this region

3192-399: Was difficult to find and from which a yellow stone (now believed to be chrysolite : yellowish olivine ) was mined in ancient times. The name topaz was first applied to the mineral now known by that name in 1737. Ancient Sri Lanka ( Tamraparni ) exported topazes to Greece and ancient Egypt, which led to the etymologically related names of the island by Alexander Polyhistor ( Topazius ) and

3249-412: Was the capital of Minas Gerais from 1720 until 1897, when the needs of government outgrew this town in the valley. The state government was moved to the new, planned city of Belo Horizonte . Population : Data from the 2010 Census ( IBGE ) The city is linked by unlit winding roads to highways for: Bordering municipalities are: Located at 1,179 m (3,868 ft) above sea level, Ouro Preto has

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