Evening star. [volume] (Washington, D.C.) 1854-1972, 1905-11-09
CUTTING DIAMONDS
RICH INDUSTRY OF ANTWERP
AND AMSTERDAM.
An Art That is Kept Secret Tn.
Three Distinct Pro-
cssses.
From the London Gr,nhlc

! From the London Graphic
| One OF the richest and most exclusive
trades. that OF diamond cutting. is now
confined so far as Europe is concerned
| which means nearly all the world-to the
| two towns CT Amsterdam and Antwerp.
and. according to a report recently FUR
nished to the foreign Office, the diamond
| trade of Antwerp now equals IL IL does
| not surpass, that OF Its great rival.
At present the bulk of the diamond supply
comes from British possessions, or mines
! owned by British subjects; and the dia-
| monds arc sent to London TO be sorted and
put UP for sale. and. though they 60
abroad to be cut. they are often returned
| TO be sold
The diihculty In the way OF developing a
| British diamond cutting industry is that OF
| teaching the British workman an art which
| the present diamond cutters keep very Sc
| ctet The Antwerp factories, Il may be
| added are principally conducted by Jews
| as are those of Amsterdam; and n system
| of apprenticeship IS In force
| Diamond cutting Is divided into three
| separate and distinct processes which may
| oe classed under the following heads: First
| cleaviug; secondly the giving OF rough
| formation TO the diamond Ccalled "bru-
| tage'). and. thirdly. cutting and polishing.
! The process OF cleaving IL the act Of diyid-
/ ing the layers or scales which form the
| crystal This operation can only be per
| formed in one manner, which It il imUos-
sible To vary on account Of the haRy fnrrua-
| ton of the diamond The stones have 10
| be divided I'm accordance with the running
| grain OF the carbon Of which they are com
| posed. "Brutage" is performed by me-
che nicallE rubbing one stone against an
other uI!til. the desired formation is
achieved. 'Pofshing'' Is tho final forming
o. the stone. with its many cut surfaces so
as to give it sparkle ana scintilating
beauty.
Nodded in Aluminium
a diamond is cleft as follows: The rough
stone Is placed In a small metal receptacle.
with the side of the diamond which Il il
desired 20 cut facing downward. Over this
! receptacle is fixed a shaped mold, which
! is securely attached to &. Into the top OF
this mold is then poured liquid aluminium.
which runs into TIE shape of the mold and
| after being cooled. securely holds the dla-
mond In the required position. The mold IS
| then removed and the stone remains fixed In
the aluminium, ready to be applied to the
! cutting tool.
The machine used Uhe invention of a Bel
CLAN working in the United States) for this
cleaving is small circular saw OF about
! four to five inches in diameter, which ro-
! tates at high rate of speed and Is driven
in the ordinary way by leather belt from
the running machinery. The saw itself is
made of fairly soft copper with prepared
| edge. IL Is of vital Importance when the
! operation OF cleaving is taking place that
the should run perfectly smoothly and
not deviate from its true course.
In order to prepare the cutting edge of
| the circular sa W 1t is necessary for IL to go
! through special process by which diamond
| dust mingled with oil is forced into its
| edge. 1t Will therefore be seen that ia the
actual cutting the principle is that OF
diamond cut diamond" The operation OF
clesving a diamond frequently takes as
much as two weeks continued work 10 per
form.
The diamonds are frequently cut into
several layers hardly thicker than a stout
sheet of paper. For the rough forma lions
or 'brutage." before the final cutting
machine was invented some twenty years
ago which is now used In ali diamond fac
tories since 1t not only greatly economics
hand labor. but also saves the diamond dust
required for polishing. Two diamonds of
similar size and hardness are taken and
each is fitted into a metal cap with melted
cement.
Preserve Diamond Dust.
One cap is fixed on a rotary machine a.
parently a lathe) and the other attached to
a handle to be used as the tool is used
against wood in lathe. The stone which
rotates in the machine receives n regul2A
rounded surface, and when IT is in its re-
CURED shape the other stone is fitted into
| the machine and the process continues.
I! The diamond dust, which Is produced by
the rubbing of the stones together. falls
into a copper box called an egrisoir. or dia-
mona aust DOK, ana Is carefully preserved
for the third operation
For the cutting and polishing process the
stone which has been roughly shaped by
the second operation, is placed In position
at the required angle in q copper holder.
into which II is firmly fixed by means Of
a forked clamp which is pressed against
the stone and locked into position with
key. Great skill is required on the part Of
the worlkmen in fixing the diamond into the
holder, Will be understood when II is
stated that many stones of one-eighth of
an inch and less in diameter. weighing be-
tween one and two grains. have as many
as fifty to one hundred facets, separate
cut faces, each at n different angle
Contiual practice. however, facilitates this
OPERATION, and skilled workman can i'm
mediately place the stone IN the holder 1t
the required angle ready for the cutting Of
another facet. When the stone is ready I'm
the holder IL is placed against a revolving
disk of soft steel rotating in a horizontal
position at speed of some 5000 revolu-
lions to the minute and is left there until
the required facet is cut and pol. shed. The
surface of this disk is prepared with mix
ture of diamond dust and purified olive oil,
which is rubbed into the steel
All diamonds are cut in a series of stars.
one being formed over the other. On look
ing through the fat surface or table Of a
properly cut brilliant the colette, lowest
point should appear to be directly In the
center of the table On the regular cutting
Of these facets depends the whole beauty
of diamond. and I'm their formation lie
the secret and difficulty of the diamond
trade.
HEBREWS REJOICE