ORES OF FIVE MINOR METALS 125
distribution is coincident with the great folding and fracturing
of the Middle Kainozoic mountain system.
ANTIMONY
Antimony (Sb; at. wt, 1202; sp. gr., 6-7; melting
point, 1150° F,; volatilization-point, 2700° F.) is a minor
metal of which the distribution offers an interesting contrast to
that of most other ores. It is a constituent of an unusually
large number of mineral species owing to its three-fold
chemical valency and three oxides, the trioxide, tetroxide,
and pentoxide (SbyOj Sb,0,, and Sby0j), its readiness to
form alloys, and its strong affinity for sulphur. It occurs in
many sulphides combined with silver, lead, copper, mercury,
and iron. It is used to harden many alloys such as Britannia
metal and pewter (which contains from 5 to 24 per cent. of
antimony), and ** white metal ’ which is used for bearings.
Its most important alloy is printers’ metal, in which the anti-
mony renders the type more durable and also clearer by expan-
sion on solidification. Antimony is also used for pigments and
drugs. The metal is of a silvery white colour, has a high
lustre, but is too brittle for use unalloyed ; it is known as
“antimony regulus,” and its ordinary range in price has been
from £25 to £45 per ton, occasionally rising to £90; during
the War owing to its use for hardening shrapnel bullets, the
Price rose to £130 per ton. Early in 1927 it was about £50
per ton. Owing to the large supplies available the price
must be expected to fall until it exceeds the pre-war average
only by the increase in cost of production.
The chief producing country is Central China, where anti-
mony occurs mainly in the province of Hunan, S. of the
Yangtze-kiang. These deposits have since 1897 enabled
China to produce sometimes go per cent. of the world’s out-
put. The production of antimony in recent times has usually
varied between 10,000 and 20,000 tons. During the War it
rose to 80,000 tons. China in 1924 produced 78-3 per cent. of
the world's total, the balance coming from twenty-five States.
France, the second producer, yielded 4} per cent., Algeria
followed with 3-3 per cent., Bolivia 2-7 per cent., and Mexico
2:6 per cent; the output from Australia had fallen to 1-8
per cent. The United States produces a thousandth of the
