According to Mr. Francis C. Nicholas", many of the diamond deposits of Brazil could be worked by dredging.
Nearly all of the diamonds found in Bahia, Brazil, as well as the carbons, are sent to Paris.b The
yearly exports increased steadily from 1899 to 1902, after which they
fell off. The outlook for a larger trade, however, was better during
1906. The yearly production of carbons from Bahia is estimated at
30,000 carats, all of which go to Paris for distribution, about 10,000
carats being taken by New York.
With
the increasing price of diamonds and the failure of the large mines to
overstock the market, there has been much activity in prospecting and
searching for these stones in many parts of the world during 1906. At
the same time, according to Consul George L. Andersonc, of
Rio de Janeiro, stock-jobbing companies have chosen the diamond fields
of Brazil for the promotion of their wild-cat speculations and have
sold much stock in London, New York, and Chicago. In many cases they
have had bad titles for their land, or do not even know its location.
The diamonds occur in scattered deposits or pockets, often in places
difficult to reach with machinery and equipment necessary for mining.
Preliminary or hasty examinations do not suffice to prove the richness
of a deposit, and often considerable money is necessary to have the
properties examined and carefully tested.
Writing
at a later date/ Consul Anderson states that mining conditions are
becoming better and that the bulk of the diamond production from the
Diamantina district still goes to Paris and London, though American
mining concerns are purchasing larger quantities of stones and
increasing the imports into the United States. The production of
diamonds can not be given with any degree of accuracy, since the State
government imposes a tax on all stones exported, and the producers try
to avoid this by keeping no records of their finds or sales. The
average production of the Diamantina region is estimated at about
5,000 carats per month, valued at somewhat over $40 per carat in the
rough.
INDIA.
The outpute of
diamonds in India is given for 1905 as 172.41 carats, valued at £2,474,
as against 286.48 carats, valued at £2,636, in 1904. The industry
furnishes employment to 1,890 persons.
The
mode of occurrence of the diamonds in the Bundelkhand States,
especially in Panna, is fully described by Mr. E. Vredeuburg in the
Records of the Geological Survey of India for 1096.'
NEW SOUTH WALES.
An
interesting discovery of diamonds in matrix has been made at Oakey
Creek, near Inverell, New South Wales/' Two miners were driving a
tunnel through a granite hill to penetrate a basalt-capped deep-lead
deposit of stream tin and alluvial diamonds. Three intrusive horn-
(•Min.
World, March 23, 1907. &Jew. Circ. Weekly, February 14,1906. cU. S.
Dally Cons. Repts., July 16, 1906. d Idem, May 15,1907.
eRec. Geol. Survey India, vol. 34, pt. 2, 1900, p. 53.
/Vredenburg, E., Rec. Geol. Survev India, vol. 33, pt. 4, 1906, pp. 273-311: also same volume, pt. 2, pp. 88-90. a David, T. W. Edgeworth, Min. and Sci. Press, January 12,1907.
