The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1901-09-15
THE CUTTING OF DIAMONDS.
MIR. j. G. Sipe Talks Interestingly on
the Subject.


Mr.. ]. c. Sipe recently returned from a
trip to Amsterdam, where he saw much of
the cleaving. cutting and polishing Of dia-
monds. To a Journal reporter he talked
interestingly of the matter He said:
THE diamond, when mined, is very often
of a shape so uneven that, in preference to
cutting half off and letting that part go
to dust, as was formerly done, incisions
are now made running with the grain of
the diamond. The incision is made with
the sharp edge Of another diamond. The
cleaving knife is then inserted and given
a sharp tap and the stone will split as
the grain runs, and thus two or more
smaller but better shaped diamonds are
made.
AFTER the diamond is cleft II Is neces-
sary TO do the rough cutting technically
known as 'bruting.' This is done by sf-
fixing two diamonds on the ends of two
lockwood sticks with a very hard cement;
one is then rubbed against the other and
diamond cuts diamond They are held
over cutting box having two iron pegs
for levers, and containing finely perforated
brass pans. through which the dust falls,
the chips remaining in the top pan.
THE stone having been cut to the salts
ishing room, where setter selects a suit
able-sized brass cup, called a dope fills
it with a mixture of lead and tin, and
melts it in a gas flame. Having worked the
solder to its proper shape, he places the
diamond in the center. leaving only very
small part exposed. mark Is made on
the solder before it becomes thoroughly
set, and then the stone is passed on to the
@1.~ 81 j.
the latter knows at the precise run
Of the grain and the way in which 1t will
polish to the best advantage on the mill.
THE first operation is the making Of the
table of the diamond. This done, it is
handed back to the setter that he may take
it out of the solder and reset it for the first
corner, called the fat corner. The solder
is again marked to indicate TO the polisher
the run Of the grain of this particular cor
ner, and go the process is continued un-
til the diamond is polished throughout.
Every facet has name, and every name
denotes the grain, and how to polish that
particular facet. The polisher uses cir
cular disc, composed OF soft, porous iron,
so that as the diamond is polished away in
the form of dust 1t enters the pores OF the
iron, the result being that we have the
diamond cutting the diamond again.
Without the assistance of the diamond
dust the iron would not make the slightest
impression on the diamond. The polish
ing wheel or disc is propelled by steam
power, and makes 1900 to 5000 revolutions
in minute. Before the silently revolving
discs you will see men so intent upon their
work that they have eyes for nothing
else; for, notwithstanding the perfection
of the machinery, the skill OF the work
men remains of primal Importance. 1t is
with their fingers and thumbs that they ad-
just the points, edges and facets of the
diamond with extreme accuracy, keeping
them constantly moist with diamond dust
and olive oil. The thumbs of the workmen,
being used continually and with much
force, become greatly enlarged
THE beauty Of 81 cut or finished stone
depends so much upon the form and po-
sition Of the facets that moderately fine
stone, we'll cut and polished, is of far
greater value than a large one less ar
tistically worked 1t sometimes happens
that the laDidary receives a stone of very
unfortunate shape; his duty will, there
fore, be to take all possible care to pre-
serve it's size; and, hiding it's faults, give
it such a form as shall send it forth with
the greatest weight consistent with beauty
and brilliancy'