The Idaho world. [volume] (Idaho City, Idaho Territory) 1864-1918, 1866-04-21
TIN.

/ fore refuse decree in this case.
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TIN.
Although tin is in such extensive and al
most universal use, and has been known iron
very remote antiquity, the localities from
which it is derived are comparatively so few
that most persons who are not mineral egsts
or who have not travelled in the mining re
gions of Cornwall, Bohemia or Saxony, ar
entirely unacQuainted even with the externa
appearance of its ores. No tin has yet beer
produced in the United States, although the
ore has been discovered in several fferen
localities At only two of these, however
has any attempt been made to mine it, in
New Hampshire and in Southern California
and only the first named of these mines is, SC
far as is known, at present in operation. Dis
coveries of tin are frequently announced
from different parts of our Pacific mining re-
gions, some of which are no doubt correct,
while in many cases some other mineral has
almost certainly neen mistaken for tin ore.
A brief description, therefore, Of the appear
ance, ETC., of tin ores and OF their mode OF
occurrence may prove useful to many of the
explorers OF our new mining regions. There
are but two, or possibly three, minerals OF
tin, though it occurs in small quantities in
some other rare substances. Two of these,
however, tin pyrites Ia mineral resembling
bronze in appearance, composed of sulphu-
rets of tin, copper, iron and sometimes zinc)
and stannite Ia yellowish, white, siliceons
mineral, probably only mechanical mixture
of quartz and oxide of TIM are rare minerals
found at only one or two localities. The
only ore of tin is the oxide known to miners
as tin stone" and called by mineralogists
q capiterite." This, which contains when
pure, 1888 per cent. of tin, occurs in crys-
tails generally of brown or black color,
though sometimes red, gray, white or yellow,
which have in most cases q very brilliant
lustre, and vary from perfect transparency to
almost complete opacity Fine crystals in
deed, bear much more resemblance in ap-
pearance to some precious stone than to
metallic ore, and have in some cases been
cut and used in jewelry. It's great hardness
too, which is nearly equal to that of quartz,
increases the resemb lance but its weight
will at once remove any doubt which may
be entertained, its specific gravity varying
from 6,3 to IL, which is far higher than
those of any of the ores of iron, of iron or
copper pyrites, ruby silver or metallic anti
mony, and not much short of that of iron,
or of tin itself, which is only Z 285. The
oxide of no other metal approaches so nearly
in specific gravity from the metal from which
It IS derived. Tin ore also occurs in fbrous
and radiated forms it is generally found in
veins traversing granite, gneiss, mica or clay
slate, or porphyry, and associated With fuor-
spar, apatite. topaz, bende, arsenicsi iron
ind wolfram. The last named mineral,
which is a tungstate of iron and Manganese,
If dark, graysh or brownish black color,
with a somewhat metallic lustfe.
much softer than tin ore, but still heavier
han it, is very injurious when mixed in large
as from the fact of its specific |
gravity I'll to 1867 being SO nearly the same
IS that of tin ore, it is almost impossible to
eparate them effectually by washing, while
f they are smelted together, the quality of
he tin produced is very inferior. Attempts
ave been made to apply the tungstic acid !
obtained from vol fran to some useful pur-
'oses in the arts, so as to allow of the profit |
BILE employment of more elaborate means of
eparation but hitherto with only partial
rccess. Tin ore, like gold, is only mechan-
cally mixed with the foreign substances
Which accompany it, and can consequently |
re brought up by washing and mechanical
NPeA"eAoH @AOHOt ~ q W
early approaching that of the pure oxide
ifferlng in this respect from most of the
res of copper and silver, in which either the
are chemically combined, or the
ore'gn substances are SO nearly the same
peciic gravity or SO intimately united that
he most careful working canno: raise the
ercentagc of metal beyond certain point.
! very large proportion of the tin product
t the world, however is not obtained from
ems but from alluyial deposits, in which
he ore exists in the form of sand or of
ounded pebbles which are know as '.stream
in" and from which it is obtained by wash
ng in the same way AS gold. The tn made
rom this is of superior quality, as the long
ontinued, grinding action of the streams by
7hich 1t has been removed from lis veins,
ogether with exposure to the atmosphere,
ave deprived it almost completely of all in
nrious intermixtnres. The Jumps and grains
t stream tin bear a strong resemblance to
oiled pebbles of brown or red jasper, or of
ematite iron ore, though they are. some
ines nearly black, but may be easily distin-
uished from both, but especially from the
rst, by their great weight, and from the last
AIMED from their hardness. IF, therefore,
erson exploring new mining region finds
n alluvial deposits, river beds, etc., associa-
ed with gold in placer diggings, small peb-
les aud sand of brown, reddish or nearly
lack color, hard enough to scratch glass,
n - 49,, -, L 1