Clarke courier. [volume] (Berryville, Va.) 1869-1997, 1903-09-16
NATIVE PLATINUM.
The "Nobie" Metals Extracted From
This Peculiar Substance


On the slopes OF the Urai mountains
ana I'm Brazil. California. Australia,
Canada and many other countries a pc
@uliar substance known as native plati-
mum is found. This is an alloy OF the
metals platinum. palladium. Iridium,
osnium. rhodium and ruthenium, to-
eether with a little gold and iron. All
o. these except the last mentioned are
tfe noble" metals. They do not tar
nssh I'm the air and are not soluble I'm
sny single acid. The most plentiful
metal occurring I'm native platinum IN
that from which IL takes its name.
This metal Is OF n grayish color and
with one exception Is the heaviest sub
stance known. Its fusing point IL ex-
tremely high. and this property, to-
gether with its freedom from tarnish-
ing. causes II to be largely used for the
manufacture OF crucibles and other
vessels required by scientists to stand
n very high temperature. IL is also
sometimes used as n substitute for gold
i'm photography. and when deposited in
thin film on the interior OF the tubes
OF telescopes IL forms n dead black
surface. which prevents the light from
being reflected by the polished sides
Palladium is OF a lustrous white
color. IL Is the most easily fused OF
the metals found I'm platinum ore, and
can even be volatilized A curious
quality which this metal possesses is
that when heated 20 redness II is
porous 10 hydrogen gas. allowing II to
pass through somewhat i'm the same
manner thar blotting paper permits the
passage OF water. The silvery white
color OF palladium and its freedom
from furnishing render il useful for
making scales and division marks on
scientific instruments. mixture OF
this metal with mercury Is sometimes
used for filling teeth Osmium Is a
metal which possesses two remarkable
properties-it is the most refractory
OF the metals. resisting fusion at the
most intense heat. and il is also the
heaviest substance known. being TWEEN
ty-twO and half times heavier than
water. Together with iridium. il oc-
ours principally in n peculiar variety OF
native platinum called osmiridlum.
This mineral differs from ordinary
platinum ore in that il contains n
larger proportion of osmum and irid-
ium than platinum. Osmiridium is
found I'm small particles. varying i'm
weight from one-Sixth to one-third OF
a grain. These particles are extremely
hard and are used for pointing nou-
wearing pens
Metallic iridium possesses white
steel-like appearance. The knife edges
OF delicate balances and other bearings
which require extreme hardness are
often made OF IL. An alloy OF 10 per
cent iridium and ~ per cent platinum
has been found To be- very little affected
I'm volume 10y changes of tempcratur
and is the substance OF which the
standard meter kept I'm the internatlon-
al metric bureau at Paris is made.
Rhodium and ruthenium are metals OF
little practical use. The former occurs
I'm platinum ore 10 the extent Of To
per cent. The latter is found only I'm
Osmiridium ami Averages about > per
cent OF that mineral. The metal which
ranks next 10 platinum in price is zir-
conium. which occurs I'm hyacnth and
some other rare minerals. Uranium IS
remarkable FOR its high atomic weight,
the heaviest known.-Chambcrs' Jour
nal