The herald., 1896-02-16

9uOp IN the euOurDS or Boston, where
he taught some young men how to Gu
| diamonds.
Presently the Dutch workmen, be-
lieving that their work WAS indispen-
sable to their employers, made exorhi-
tant demands on them. Mr.. Morse
thereupon turned them eff and put his
young Americans to work. From that
time diamond cutting became subject
to competition, with the best possible
results to the trade.
The scheme of the Maiden lane peo-
pie WAS blasted, but for all that the
Amsterdam cutters have been coming
here in a steady stream, and today
there are probably more diamonds cut
in New York than in any other large
city the world over. Some of the great
Amsterdam firms have been forced to
follow the trend of the trade, and sew
eral of them within the last year have
moved their entire establishments
here, including machinery and equip
ments. They could not bring their old
employees under contract. but they
were nominally discharged, and later
on drifted into this country and were
re-engaged.
Compared with the work OF genera
tion ago, the cutting of diamonds is
now quite simple. Workmen of extra
ordinary skill, of course, earn good
pay, but the average wages are not
more than those paid to the skilled
mechanic in general.
Machinery does most of the work
From the rough to the finish the dis-
mond passes through four stages. The
rough diamond is fastened in cement
at the end of a tool. Another rough
diamond is fastened in the same way
to similar tool, and the two are
rubbed together until the very sharp
points have been removed. This is lit
orally diamond cutting diamond. The
rubbing process is performed over q
small box, into which falls the iia
mond dust. Later on this dust Is
used on the steel wheel in grinding.
After the sharp points have beal
removed the diamond is sunk in metal,
which is heated to a sufficient degree
to hold the gem. The metal is in the
form of sphere, and is held in cup
shaped tool. This is held in a wise
over the swiftly revolving steel wheel,
and the diamond dust does the cutting.
The old fashioned way was to use pc
culiar kind of sand, but the labor vas
enormous and the results comparative
ly poor.
It is peculiar fact that some die-
monds are harder than others. Hence
it is impossible to grind some dia-
monds with the dust Of others. Only
their own dust can be used on these
tough gems. The black diamonds of
Borneo, for instance, cannot be ground
except when their own dust is used on
the grinding stone.
Apropos of this, the safest way to
determine the genuinenese of of dia-
mond is to test its hardness. The
sim plest test is to hold the stone firm
ly against wet, rapidly revolving
grindstone from five to ten minutes.
If the least mark appears upon the
piece il is hot diamond, for il it we're
a diamond, so far from any mark being
produced on it, it would be likely, on
the other hand, to make deep i'm
preston in the grindstoDe. The same
test may be made Hith emery paper, or
ar emery wheel, neither of which,
harder than grindstone,
will make any impression upon a dia-
mOud.
This is a good thing for the prospect
i've buyers to remember in these day S
of manufactured diamonds. The paste
article is made with such care that it
sometimes tests the skill OF the expert
to distinguish the genuine from the bo-
gus, but if the grind stone is brought
into play there can be DO room for
doubt. Some people think that if they
rub q stone against glass and it makes
a deep impression it is diamond.
Some paste articles will scratch glass,
and the imitation of sapphires, rubies
and emeralds will do the same.
Regarding the hardness of the dia-
monds. the expert at Tifany's said:
"In 1886 made en experiment. The
stone here was a round piecs Of Brazil.
ian borf, with radiated internal struc-
ture. 1t was kept on polishing wheel
made of hard iron, with a diameter of
one foot, for seven and one half hours
a day for nine months, the wheel turn.
ing at the rate Of $500 to 1900 revolt
tions per minute, and giving three feet
OF travelling surface to the stone. The
total distance traveraed was 10000
miles, or about seven times the circum-
ference Of the globe, but the result was
the polishing OF only about one square
centimeter of surface. With an crdi-
nary diamond fully hundred times as
much would have been accomplished"
So if man wants to sell a real dia-
mond, and he knows that it is genuine,
he will not be afraid to test it on