In
Brazil, there are no deposits in the strict sense of the word, but
corundum gems are nevertheless occasionally found at rare intervals in
the process of washing diamond gravel.
Corundum stones have been produced in India for many centuries the
sapphire fetching prices from 100 milreis to 7,500 milreis a carat,
while the value of the ruby varies between 250 milreis and 40,000
milreis a carat. The Australian sapphire which contains green or yellow
hues and is at times tool opaque, brings lower prices, ranging from 15
milreis to 250 milreis a carat.
The
sapphire occurs in Brazil as a satellite of diamond in Diamanti-na in
the state of Minas Gerais; in Salobro in the Minas do Rio das Contas
and Recreio in the state of Baia; Jauru and Quilombo in the state of
Mato Grosso; Cachoeira das Escadinhas in the state of Espirito Santo
and Serra do Itaqui, Rio Canoas, Rio Sapuci and Rio Santa Barbara in
the state of Sao Paulo.
Rubies
have been found at Abaete, Abadia dos Dourados, and Agua Suja in the
state of Minas Gerais; at Rio Paraguassu, Rio Camassari, Jequie and
Andrade in the state of Baia; at Rio Piuma in Espirito Santo State and
in the Coxim and Jauru Rivers in the state of Mato Grosso.
14. PYRITES
The
importance of pyrites lies in the sulfur it contains which even-tually
is utilized principally in the manufacture of sulfuric acid. To this
appli- cation, may be added that in other chemicals, that for
fertilizer and insecti-cides, pulp and paper, explosives, dyes, rubber,
etc. In Brazil, the larger part enters into the manufacture of sulfuric
acid, insecticides, rubber and explosives
In
Brazil, there are no known occurrences or deposits of brimstones. Thus,
the only local source of sulfur is pyrite, a sulfide of iron which is
often confused with gold. Among world producers, Brazil is of
insignificance in the production of this mineral, being in 25th place
with the admission that the total output of Brazil is that of the state
of Minas Gerais alone. The absence of data from other producing states
does not permit the correct collocation of this country. Spain, Japan
and Norway are the principal world producers. The leading world
producers of native sulfur are the United States, Italy and Japan.
Pyrites
are found in nearly all parts of the country in small quanti-ties but
veritable deposits are encontered in but few places. And even as such,
the greater quantity is found containing gold, especially those which
occur in veins associated with arsenified minerals. The presence of the
latter and gold thus gives rise to the extraction of gold and arsenic
and the sacrificing of the sulfur content. As such, there are only two
deposits being worked strictly for the sulfur, that of the Ouro Preto
district in the state of Minas Gerais and the Rio Claro deposit in
Estado do Rio.
The
Ouro Preto mineral is formed in layers containing small crystals of
nearly pure pyrite, there being little or no arsenic which is
undesirable in the manufacture of sulfuric acid. The sulfur content is
42.40% and is refined
