The Colfax chronicle., 1903-06-20
rHE MORE PRECIOUS METALS.
Iateresting Fact. About the "Nobler
Metals That Have Recently
Come Into Use.

than gold, writer in Chambers
the UraI mountains, and in Brazil,
California, Australia. Canada and
many other countries, "a peculiar sub
stance known as native platinum is
found. This is an alloy of the met
ais platinum, palladium. iridium,
gether with little gold and iron.
All of these except the last men,
toned are noble" metals. They do
not tarnish in the air, and are not
soluble in any single acid. Their
values per ounce are: Platinum,
95s.; palladium, 1905; osmium, 200s.;
iridium. 250s-: rhodium, 400s., and
rutbeniam. 45os. The most plentiful
metal occurring in native platinum is
that from which it takes it's name.
This metal is of a grayish color, and,
with one exception, is the heaviest
substance known. Its fusing point
is extremely high, and this property,
together with its freedom from tar
nishing, causes il to be largely used
for the manufacture of crucibles and
other vessels required by scientists.
1t is also sometimes used as a sub
stitute for gold in photography, and
when deposited in thin film on the
interior of the tubes of telescopes it
forms a dead-black surface. which
prevents the light from being re-
fa1 hxr he s.h al "a
demand for platinum largely exceeds
the supply: hence the metal is year
ly advancing in price.
Palladium is of lustrous white
color. Ii is the most easily fused OF
the metals found in. platinum ore and
quality which this metal possesses is
that when heated TO redness it is
porous to hydrogen gas, allowing ii
to pass through somewhat in the
same manner that blotting paper per-
mits the passage of water. The sill.
very white color of palladium and
its freedom from furnishing render
il useful for making scales and di-
vision marks on scientific instru.
ments. 4 mixture of this metal with
mercury is sometimes used for stop
ping teeth. Osmium is metal which
possesses two remarkable properties;
it is the most refractory of the met
| ais, resisting fusion at the most in
tense heat, and il is also the heavi
est substance known, being almos,
22H times heavier than water. To
| gether with iridium. il occurs princi
pally in peculiar variety of native
| platinum called osmiridium. This
mineral differs from ordinary plat
mum ore in that ii contains largcI
proportion of osmium and iridium
than platinum. Osmiridium is fount
in small particles. varying in weight
from one-sixth to one-third of Z
| grain. These particles are extremely
hard and are used for pointing non
wearing pens. For this purpose al
much as 30 ounces of osmiridium art
used annually in the United States
This mineral is source of mucl
! trouble to the officials of the Russian
mint. who find it extremely difficult
to separate small particles of is from
the gold used for coinage.
Metallic iridium possesses a white
steel-like appearance. The knife
edges of delicate balances and othel
bearings which require extreme hard
ness are often made of it. An allo,
of ten per cent. iridium and 90 pc
cent. platinum has been found 10 b'
very little affected in volume b.
| changes of temperature. and is th'
substance of which the stanoar,
metre. kept in the lnternationa
Metric Bureau at Paris, is made
| Rhodium and ruthenium are metal
| of little practical use. The forme'
occurs in platinum ore to the exten
| of five per cent. to six per cent. Th'
latter is found only osmiridium, ant
averages about five per cent. of tha
| mineral. These six metals have beel
treated of together because of thei
resemblance to each other; but tn
| metal which ranks next to platinum
in price is chromium, which occurs il
hyacinth and some other rare mir
erals. and is worth about &c pc
| ounce. Titanium and ura anium, who's
| ores are found in Cornwall and som
other places. are each worth 96 los
per ounce. Uranium is remarkabl
for its high atomic weight, the heay
lest known.