Year: 1863

As the attention of prospectors, in Califor-
MIA, at this time, appears to be very general
ly directed to copper, as apresent speciality
we haye thought it might be opportune to
give few hints which may be of service in
such researches, and which we find in the
Mining and SCIENTIFIC Press.


The ores of copper are quite numerous and
present great diversity of appearance yet
they are all very readily distinguished by
certain chemical re agents, from nom copper
Gus ores. The presence ofcopper in any ore,
even to as low per centage as fraction of
only one per cent. may be readily ascertained
by first calcining and then finely pulverising
the ore and subjecting it to bath of water
OF ammonia, when, if copper is present, the
water of ammonia, when. ifcopper is present
the water will assume blue tinge, more or
less intense, according to the amount of cop
per In the ore. teaspoonful of pulverised
ore dropped into two ounce vial two thirds
filled with the above mentioned liquid is about
the proper proportions to be employed in the
test Nearly all the ores of copper may be
readily distinguished, after little experience
from the appearance of a greenish tint upon
their surface, more or less observable, and
sometimes verging upon purple or blue.





lurgists, into l3 different classes, and each
class is subdivided into many varieties. The
richest of the ordinary ores under two gener-
al aspects; the first having a METALLIC lqstre
of copper red, brass yellow, iron or blackish
gray, at times ipelining to blue; the second
is without metallic appearance of reddish col.
or, verging upon purple. blue or green, the
last being the most usual tint. The classes
OF ore most frequently occurring are Native
Copper, Sulphuret of Copper, Copper Pyrites,
Gray Copper. Sulphathe Of Copper, Carbon.
ate OF Copper and Arseniate ofCopper. Ma
tive Copper, so far as we have learned has
never been found, to any extent in this State,
although it occurs in greater or less ahun-
dance IN most other copper regions hitherto
explored. 1t is found in greatest abundance
in the mines on tie Southern shore of Lake
Superior. The most common ore of copper
are sulphurets ard oxides, the former being
the most abundant


Sulphuret OF Copper occurs in all consider
able copper districts, and especially in Corn
wall. This is also a class of ore which seems
to be very abundant in California The col
or of this ore is blackish lead gray, approach
ing, at times to tarnish blue or green 1t is
considered one OF the richest ores, and gen
orally occurs in very heavy veins.


GQpper Pyrites greatly resembles, in ap-
pearancc, sulphurct of iron. common in the
gold bearing quartz of this State, and will
probably prove the most abundant of the cop
per ores on the Pacific Coast. This with the
sulphuret of copper, forms the chief yield of
the copper mines Of Cornwall. The color of
the Pyrites is bFess yellow. subject to tarnish,
with greenis!h black streak and uneven frac.
ture.


Copper Pyrites are readily distinguished
FROM iron pyrites, WHICH they greatly resem
BILE, by their inferior hardness they may be
cut with knife, while iron pyrites will strike
fire with steel a marked difference may
also be noticed in the effects os nitric acid
upon the two substances. They do not form
50 rich an ore as sulphurets. The richness
of the Pyrites may generally be judged by
their color. If they present fine yellow hue
and readily yield to the hammer, they may
DE considered good ore; bnt if they are
hard and Of pale yellow color, they ere mix
ed iron pyrites, and consequently compare
lively barren of copper and constitute poor
quality of ore.


Carbonate of copper is of a light blue or
green color, with pale green streak. 1t often
occurs in beautiful green chrystals. 1t is
also known as Malachite. Green Malachite
or Green Carbonate of copper admits of
high polish, like marble, and when obtained
in large slabs, is often formed into tables,
mantle pieces, etc.


Arseniate of fcopper is of various shades of
olive green, and sometimes occurs in beauti-
full blue chrystals. 1t readily melts before
the blow pipe, throwing off fumes of garlic
odor. This ore is but little worked.


Gray copper ore is of e steel gray color
H. ILL
The value of this ore is often very materially
csntains. 1t is generally accompanied, to


Sulphate of copper Blue Vitrol, is simi-
lar to the artificial salt of the laboratory
The water flowing from mines of this variety
of ore is of blue tint caused by the solution
of this salt. Copper is easily obtained from
this water, in metallic state, by deposiung
pieces cf scrap iron in it.


The ores above named are about all the
ores of copper which are worked to any ex-
tent. The copper of Lake Superior contains
about 3l0ths of one per cent. of silver. The
copper Of this State mostly if net all, doubt
less contains an arpreciable quantity of both
gold and silver. Of this we shall probably
receive more definite knowledge when full re-
turns are received from the ores which have
been shipped East for reduction Many of
the mines now being explored for copper,
have heretofore been worked for gold and
abandoned because they would not paw. As
our miners become familiar With the eharae-
teristies of copper ores these mines are being
rapidly re located, and worked for the legiti-
mate yield, which, as a general thing, viii
be found to be much more profitable and en-
during. than any ordinary yield of the more
precious mineral so generally sougat for in
California. A little science will be found of
vast importance to the practical miner every
where, and especially in California, where
the mineral deposits assume such great va.
riety, and are found in such unprecedented
profuson Our miners according to present
indications. will soon become as familiar with
copper ores, as they have, for the last ten
years. been with gold. Weshall. from time
to time take occasion to throw out such prac-
teal hints as may be deemed for the adyan-
tage oJ those engaged either il prospecting
for ores, or raising end reducing them.