available. Lately control has been extended over this industry, both in the industrial and commercial aspects.
The Casa da Moeda estimates
the production of uncut semi-precious stones as having totalled 641,412
grams in 1937 with a value of 1,795 contos while that for 1938
decreased to 577,928 grams valued at 3,614 contos. It is only in 1939
that there is data available as to output of the other types of stones,
that of uncut semi-precious stones being 1,563,833 grams in this year,
nearly 170% more than that of 1938 but only 83%' of the value. The
production of lapidated semi-precious stones is noted as being 4,874
grams during 1939 with a total value of 107 contos. Agate production
totalled 1,473 grams and was valued at 9 contos de reis. The least
important, that of rose quartz, totalled but 300 grams and a value of 3
contos.
Exports
of semi-precious stones as noted in Table 1 amounted to 3,431 contos in
1938, and decreased in 1939 to 2,007 contos. It may be noted that in
1939, the principal markets for aquamarines which was the most
important export product of this group (1,663 contos) was Germany, the
United States being secondarily important. The 170 contos of
tourmalines shipped abroad were sold principally in the German market.
Amethyst shipments valued at 129 contos were exported principally to
Germany and the United States the former taking 124 contos and the
latter 5 contos.
In
1940, the shipments of these stones increased to more than seven times
that of the previous year totalling 15,453 contos. Of this total,
aquamarines accounted for 13,469 contos or 87%, the principal market
being Germany which purchased 12,766 contos of this total. Tourmaline
was again the second largest amounting to 1,281 contos. The markets for
this stone were Germany, the United States, Switzerland and Peru.
Contrary to other years, the third largest in 1940 was topaz which in
total amounted to 197 contos while the fourth was amethyst which
totalled 195 contos. Topazes are shipped chiefly to Germany while the
latter, amethysts, are sold principally to Japan, Germany and the
United States.
There are no recorded imports of semi-precious stones.
GARNETS
The
garnets are silicates of aluminum, iron, calcium, magnesium, manganese,
and chromium. Their hardness ranges from 6.5 to 7.5, their density,
from 3.15 to 4.30 and the index of refraction, between 1.70 and 1.94.
It occurs in crystals in the form of rhomboids, decahedrons or
tetragonal tri-cctahedrons. The color varies from ruby-red to
blood-red, from light brown to almost black, from a honey color to
gray-brown and may appear in various shades of green. The most common
varieties found in Brazil are almandite (Al and Fe), pyrope (Mg and
Al), spessartite (Al and Mn) and grossularite
