Chicago eagle. [volume] (Chicago, Ill.) 1889-19??, 1901-10-19
A TALK ON GEMS.
How the Diamond 10 Cut and What Causes
Its Value,

1t was rare treat that the audience
at the Ro.cdalc School Art League Ice-
turc had on Saturday afternoon wheH
Mr.. James Ryrie. of Ryric Bros, lee.
tured on Jewels Mr.. Ryrie combin-
ed enough expert information with his
lecture to give those present peep
behind the scenes at the processes that
result in the glare Of the jewels as they
catch the buyers eye. Naturally, to the
diamond most attention was paid; and
at the very outset Mr.. Ryrie explained
that the term karat" in gold applies
to quality. pure gold being "a karats
fine. and in this form the particles fell
apart like sand, requiring an alloy Of
baser metal to hold them together.
In the case of diamonds the term
karat" means weight, and Is derived
from an Indian seed which when dry
is absolutely uniform in weight. A dia-
mond weighing 100 karats, therefore,
is one that is of the same weight as 100
of these Indian seeds. The end of All
ordinary lead pencil represents the sui
face Of stone between one and one.
half karats. The cutting of diamonds
and their polishing is done with dia-
mond dust mixed witt, oil placed upon
a wheel that revolvcs with great rapid
ity, the diamond in process of polishing
being fastened to steel arm resting
on the wheel. The facets arc cut on
mathematical lines to reflect and iefract
the rays of light, and there arc forty
eight such facets on every full cut bril-.
liant.
A rose cut stone is one not stuff.
ciently deep to admit of regular cutting,
and rather than sacrifice too mucl, in-
stead of being cut to point under
meath, it is flat, with facets on the top
This variety of diamond is only abort
one-quarter the value of brilliant Of
similar size and weight. 1t was sup-
posed by many that white was the only
color known to diamonds. As proof to
the contrary. Mr.. Ryric exhibited to his
audience two black diamonds and one
of coffee color, remarking. that they
possessed great value on account Of their
rarity.
Mr.. Ryric showed fac smiles in size
and shape Of some of the chief crown
jewels. the most notable being the great
British diamond. of which he said:
Our knowledge Of the Kohinoor, the
Indian for Mountain of Light now
the property of Our queen, dates back
to the treasury of Delhi in Is26. After
vicissitudcs it fell into the hands Of
the British o,iiery at the capture Of
Lahore. and was by them presented to
her majesty on July 3. 1850. 1t was
exhibited at the exposition in 1851, and
being somewhat imperfect a consulta-
ton Of leading scientists, Sir David
Brewster among them. thought II Nigh:
be unsafe to attempt to recut II. After
considerable discussion. however. it was
intrustcd to a Mr.. Coster, Of Amstcr.
dam, by whom is was very greatly i'm
proved, retaining nearly the original
surface size. although decreasing it very
much in weight. being reduced from
1856 to TOO karats."
Mr.. Ryrie dealt with colored stones
in an equally interesting manner. The
emerald, he said. was found in a sorl
of slate stratum in South Africa. in tn,
Ural mountains and in Egypt. Tn,
ruby and the sapphire were found il
India and Burmah. The beautiful opa
was native of Mexico. but the ocst spe'
cimens were from Australia. The tur.
quoise was found in Persia, Egypt ant
also in some portions Of the Unitet
States. One Of the characteristics o.
this stone is that it changes color with
out any apparent cause.-ToyoHt,
(Ont) Globe.