In the beginning of the month we attended the 12th Annual Brazil Free
Gem Fair in Teofilo Otoni, Minas Gerais, Brasil (5th - 9th July).
We spent way too much and bought parcels of Boulder opals, Crystal
Opals, a few pieces of Boulder Opal Rough, besides the other
Brazilian faceted colored stones and Emeralds.
Several of the principal opal dealers from the state of Piaui were
present with booths and some fine material as well as the normal
grade of Brazilian opals. (I scanned two pictures from their posters
if any one wants to see what kind of material is available.)
We had occasion to have some long conversations with these opal
dealers and got filled in a little more on the opal producing
situation in Brasil.
Apparently the Australians initiated the opal mining about 30 years
ago in the state of Piaui and one person reported that the
Australians had taken about 50 tons of material back to Australia.
(the number seems slightly excessive - though it was probably taken
on matrix).
After that, it seems the material dried up and the majority of the
Australians left. They reported that there is one company still here
and it is initiating mining again.
The actual mining of opal in the state of Piaui is done on the old
prospector system. There are a reported 2000 independent prospectors
(‘garimpeiros’) in the area, but due to a drop off in production it
was estimated that maybe 300 of them are active at the moment. Of
these 300, it was estimated that maybe ten have actual legalized
claims registered with the government. The others are mining areas
without legalized claims and defend them in the old west cowboy style
(flying lead).
It was mentioned that if one of these illegal claims was to hit a
good pay load, someone with more resources could run and register it
and be the legal owner of the claim. The registration process is very
bureaucratic and rather expensive for the level of resources available
to the average ‘garimpeiro’. It is also slow.
The opal producing companies usually finance some or all of the
prospectors and get first look at the production. They mentioned
buying and supplying basic mining equipment (picks, shovels, screens
etc.) The ‘garimpeiros’ which are producing probably get advances for
food and living expenses.
One of the opal producers informed us that they were involved in
organizing a cooperative for the ‘garimpeiros’ so as to help them get
better working and living conditions.
Due to the way the material is mined, the rough produced dribbles into
the market irregularly and is usually bought up immediately by the
local opal producers who have their own lapidaries, either as
employees or free lancers. Thus it is very difficult for the rough to
even make it down to the south of Brasil, much less out of the
country. The local lapidaries, so far, have been able to process the
material that is being produced.
They mentioned that there are on the order of 40 lapidaries in the
opal producing area. The lapidaries use tripoli powder on Felt to
polish the Opals. Here in Brasil the lapidaries and faceters use
basically only three things to polish almost everything. Tripoli
powder, White Powder (which is Aluminum Oxide), and Green powder
(which is Chrome oxide). Various combinations of all three are used
on almost everything except Corundum, Chrysoberyl and Alexandrite,
where they will mix in some diamond powder also.
The Opal dealer told me they use Tripoli powder, green powder and some
white powder for polishing Opals on hard Felt wheels.
Another recent happening was the find of orange fire opal in the state
of Rondonia, in a jungle area, on the site of an old gold mine. This
material is being mined by a foreign company and hasn’t been appearing
on the Brazilian Market. A good picture of a piece of the Brazilian
Fire Opal rough is shown on page 37 of the March/April 2000 issue of
Colored Stone Magazine (by the same publisher as Lapidary Journal) and
a brief write up on page 29. I have not seen much of the Mexican color
Cherry Red Fire Opal in Brasil - mostly more orange colors. The piece
of rough in the picture has a spot of red but the majority of the
piece is orange.
The January/February 2000 issue of Colored Stone Magazine (Tucson Show
Guide) has an article on page 518 about Brazilian Opal, starting in
the middle of the second column.
Best regards,
Robert Lowe
Lowe Associates - Brasil
Gemstones, Rough, Specimens
e-mail: @Robert