106
THE MINERAL WEALTH OF BRAZIL
metric
tons, the importation of 23,224 metric tons of 1939 having been the
largest up to that time. In that year, the principal source of the
sulfur was the United States which supplied 47% of the total. The
second largest supplier was Chile which furnished 30%. In 1940 there
was another increase to 24,100 metric tons, the record high to date, the leading sources being Chile (54%) and the United States (38%).
In
connection with the increasing sulfur imports, it is of passing in-
terest to note that the imports of sulfuric acid had decreased to an
annual aver-age of 130 tons in the 1930-4 period as compared to the
average of 400 tons during the 1920-9 decade. In the 1935-9 period
there was still a further de-crease to 20 metric tons while in 1939 it
was no longer recorded in official statistics due to its insignificance.
15. ROCK CRYSTALS
Rock
crystals were formerly used for moderate-priced jewelry, to some extent
in optical instruments and in some countries, principally Japan, for
the manufacture of seals. At the time, quality was a factor of little
importances as compared to today and the stone was quoted on the market
in tons. With the development in radiotelegraphy and radiotelephony,
short wave broadcasts, sound films and television, crystals have come
to play an important role in in-dustry, particularly as an oscillator.
Prices were then quoted in arrobas (in kilograms) and now in kilograms, so greatly has risen the value attached to them.
World
producers of rock crystals are limited, the principal being Bra- zil
which has an annual output of 2,600 metric tons. Madagascar, Japan,
Kenya. and South West Africa (Rose quartz) are of some importance.
Exports
from Brazil are by far the largest in the world due to the factor of
quality and exceeded that of the second largest exporter Madagascar by
approximately 673 metric tons in 1939.
In
the state of Minas Gerais, there arc deposits in Diamantina, Sete
Lagoas, Buenopolis, in the valley of the Jequitinhonha (rose quartz),
Bocaiuva, Grao Mogol, Itanhomi and to some extent in scattered regions
throughout the state. In 1937, Diamantina was the largest producer
accounting for 83,000 kilograms of the total of 206,640 kilograms.
Second in importance was Sete Lagoas with an output of 65,000 kilos.
In 1938, the state output totalled 368,850 kilograms an increase of 79%
over the previous year. The 1939 output was _ 583,525 kilos and that
for 1940 estimated to be 650,000 kilograms, gains of 58% and 11%
respectively.
During
1939, the principal producing municipalities in the state of Minas
"-Gerais were Curvelo and Sete Lagoas with 160,000 kilograms each,
Diaman-tinai with 76,500 kilograms and Montes Claros with 58,000
kilograms. Of secondary importance were Santa Maria do Suassi with
25,000 kilograms, Teo-filo Otoni with 22,360 kilograms and Bocaiuva
with 20,000 kilograms.
