Diamonds were known and worn as jewels (in the rough) in India 5,000
years ago and used as cutters and gravers 3,000 years ago. India was the
source of supply until diamonds were discovered in Brazil about the year
1700, when Brazil became the largest producer and remained so until
diamonds were found in South Africa about 1869. The African mines now
produce four-fifths of the diamond supply. Previous to the discoveries
in Africa, diamonds were known to originally come only from high places
in the mountains, because the diamond deposits were found in India and
Brazil, on high plateaus, on the sides of mountains, in the beds of
mountain streams, and in the plains below; where mountain torrents had
rolled them.
In Africa, for the first time, the true original home of the diamond was
found at high levels in the mountains, in enormous fissures, open
chasms, chimneys or pipes, extending to great and unknown depths. Into
these immense chimneys, nature forced from subterranean sources, slow
rivers of a peculiar blue clay, a diamondiferous earth termed
“serpentine breccia” or “volcanic tuf” and now known by the latter-day
name of “Kimberlite.” As this soft mixture oozed into the “chimneys” or
“pipes” from the bottom, it was gradually forced upwards, filling the
whole chasm from wall to wall and to the top, where its progress ended
by hardening in a small mound ten to twelve feet higher than the
surrounding surface.
In this blue clay or Kimberlite in these chimneys, is found nature’s
most wonderful creation, the diamond crystallized from pure carbon, in
intense heat, and under titanic pressure.
The greatest mines of Africa are the Jagersfontein, Wesselton, Premier
and Robert Victor. The Kimberlite of the Jagersfontein mine is free from
pyrites, and to that is attributed the remarkable brilliancy and purity
of color for which the diamonds of this mine are celebrated. Their color
includes the blue, and they command the highest prices of any diamonds.
The Wesselton mine crystals are noted for their octahedra and purity.
The color and brilliancy are so superior that nearly all fine white
“Rivers” are rated as Wesseltons. The Robert Victor yields a big average
of fine white stones, and many of the crystals are very perfect and
beautiful. The Dutoitspan diamonds mostly show color, but many are
“fancy” and demand a high price. The Bulfontein crystals are usually
small white octahedras of very good color, but many are flawed. The De
Beers stones are good white, some color, some broken crystals and smoky
stones. The Kimberly diamonds are much the same as those from the De
Beers mine. The Premier is the largest diamond mine in the world. Of its
diamonds some have an oily lustre and are quite blue--many are of the
finest quality and color. This mine also produces a large number of
“false color” stones which change color in different lights. The
Voorspoed and the Koffyfontein produce fair white and some colored
diamonds.
Diamonds in small quantities are also found in Borneo, British and Dutch
Guiana, Australia, Sumatra, China and the United States.
One of the largest diamonds known (weight 367 carats) was found in
Borneo about a century ago, and belongs to the Rajah of Mattan. One of
the most celebrated is the Koh-i-noor (Mountain of Light), belonging to
the British crown. It weighed originally nearly 800 carats, but by
subsequent recuttings has been reduced to 103-3/4 carats. The Orloff
diamond, belonging to the Emperor of Russia, weighs 195 carats; the Pitt
diamond, among the French crown jewels, 136-1/2. The former, which came
from India, has been thought to have originally formed part of the
Koh-i-noor stone. The largest Brazilian diamond weighed 254-1/2 carats
and was cut to a brilliant of 125. Some of the South African diamonds
are also very large, one being found in 1893 weighing 971 carats, or
nearly half a pound. More recently a much larger one has been found,
weighing 3,034 carats. This has been cut into eleven pieces, the
largest, a drop brilliant, weighing 516-1/2 carats. This, called the
Star of South Africa, has been placed in King George’s scepter, and
another, of 309-3/16 carats, in his crown.
A rough diamond is a hard-looking, luminous object, somewhat like a
piece of alum, with a dull skin, called the “nyf,” over a brilliant
body. The ancients wore their diamonds uncut because they could not find
a substance that would grind or cut them. About 1,500 years ago,
however, it was found that by rubbing or grinding one diamond against
another the outer skin could be removed. At Bruges, in 1450, diamonds
were first polished with diamond dust. In Holland, in 1700, diamonds
were first cut with an idea of bringing out real beauty and brilliance
by cutting them square with a large flat table and some small facets,
ten in all, sloping to the edge of the square. From this beginning
cutters gradually added additional facets to increase the brilliancy
until there were thirty-four in all. Then came the English round-cut
brilliants with fifty-eight facets, but the diamond was left thick and
lumpy, until about seventy-five years ago, when an American cutter,
Henry D. Morse, of Boston, developed the cutting of diamonds to its
present perfection by fearlessly sacrificing weight to get proportion.
This greatly increased the price of diamonds, but enhanced their
brilliancy.
[Illustration: OLD SQUARE CUT DIAMONDS]
[Illustration: ENGLISH SQUARE CUT DIAMONDS]
All cutters have been compelled to follow this method, and the perfectly
cut brilliant of today has a depth from table to culet of six-tenths of
the diameter, of which one-third is above the girdle and two-thirds
below. In this form the diamond resembles two cones united at their
bases, the upper one cut off a short distance from its base, the lower
one having its extreme point cut off. It has fifty-eight facets, of
which thirty-three, including the table, are above the girdle and
twenty-five, including the culet, below the girdle. Stones which are not
scientifically cut in this true proportion, if too deep, are called
“lumpy,” if too shallow they are called “fish eyes.” A slightly spread
stone is desirable, provided it has not lost brilliancy, and so become a
“fish eye.” Looking larger than its weight indicates, it offers a larger
appearing diamond for the price of a smaller perfectly cut stone. Most
cutters remove as little of the rough stone as possible in cutting so as
to retain weight (they sell by weight). This often results in the
finished diamond being too thick at the girdle, making a lumpy stone.
Many people think deep, lumpy stones are most desirable. This is not
true, as they are imperfectly cut.
In preparing to cut a diamond the rough crystal is studied until the
grain is found. Along the grain another sharp-pointed diamond is ground
until there is a V-shape incision or nick. The blunt end of a flat piece
of steel is placed in this nick and a smart blow of a hammer divides the
crystal evenly and perfectly. After this “cleavage” has removed the
unnecessary portions, or they have been sawed off by the use of
rapidly-revolving thin wheels charged with diamond dust, the diamond is
set in a turning wheel and ground with another diamond until it takes
the shape in which we know it.
The fifty-eight facets are cut and polished one at a time on a
rapidly-revolving wheel charged with diamond dust and oil. It takes from
two and one-half to four days to properly cut a stone. Knife-edge girdle
diamonds are impractical owing to the liability of chipping the thin
edge in setting or by blows while being worn. Polishing the rough edge
of the girdle is rarely done and then usually to conceal a girdle which
is too thick or lumpy. The principal diamond cutting centers are
Amsterdam, Antwerp and New York.
[Illustration]
Inherent flaws can be perfectly understood by imagining a pond of water
frozen solidly to its center. At the shore, where the ice has been
partly forced out along the banks, it will be full of grass, leaves,
pebbles and sticks, and presents a broken and frosted appearance.
Further out there are only traces of such débris, some bubbles, spots,
etc. Out at the center is clear, transparent, unbroken, unflawed, purest
blue-white ice, such as you delight to see in your glass on a hot day.
So is it with diamonds; some (like the ice along the shore) are full of
cracks, carbon specks, bubbles, clouds, splits and cavities; some have
all of these; some only a few; others only one, and some are without
flaws.
[Illustration]
Of all the imperfections (not considering glaring cracks or nicks),
carbon spots are the most discernible. They range from mere specks
scarcely visible with a powerful magnifying glass, to large black spots
or clusters of large or small black specks sometimes quite plain to the
naked eye. These are carbon which failed to crystallize with the rest of
the diamond, or intrusions of titanic iron. The blackest and often most
numerous carbon specks occur in the finest white and blue-white stones.
“Capes” and other yellow diamonds are usually perfect, something in the
color of these stones seemingly being of a nature which helps clear and
perfect crystallization. Blue-white stones of exceptionally fine color
are often massed full of shaggy or jet-black carbon spots.
White specks and bubbles are common flaws, which vary in size and which
may be best illustrated by looking at a pane of glass in your window.
There you will find small knots, white bubbles and whitish specks.
These seldom injure the brilliancy, as they are often a glittering
silver color, more brilliant than the diamond.
Clouds are dark flat patches in the grain, of a brownish color, and
appear as a sprinkling of dust in a small patch in the interior. This
seldom injures brilliancy.
Glessen or glasses are flat sectional streaks having an icy appearance.
When large or abundant they disturb or cut off the proper reflection of
the interior light rays, causing an appearance known as “shivery.” When
clouds or glessen occur at the surface of a diamond they appear as
cracks, and if at or near the girdle are dangerous, as the stone is
liable to split or crack there when being mounted or by any hard blow,
which would result in the loss of a sliver or wedged-shaped piece out of
the edge.
[Illustration]
Surface flaws consist of nicks or cavities in the face of the stone
either above or below the girdle. The brilliancy of the diamond hides
these flaws when the diamond is clean, but when clouded with soap and
dust these cavities fill up and show plainly.
[Illustration]
Diamonds are so brilliant, the radiance from the facets so bewildering
to the eye, that the flaws cannot be seen by the human eye unless the
imperfection is pronounced and at the top surface of the diamond. Each
facet of a diamond (by reason of the method of cutting) is a window
looking down a clearly defined walled chamber, like a hall-way to the
culet. With a one-inch loup or magnifying glass such as watchmakers and
diamond dealers use, it is possible to clearly look down through each
facet and its hall-way to the culet, and observe throughout each chamber
the very slightest imperfection if one exists, thus thoroughly examining
and exploring the entire diamond.
Diamond brilliancy is of two kinds: “surface brilliancy” and “internal
brilliancy.” Light falling vertically on a diamond is reflected back in
straight, unbroken rays. This constitutes “surface brilliancy.” Light
falling in a slanting direction is partly reflected and partly enters
the stone; that part which enters is refracted or bent and causes the
“internal brilliancy.”
In a perfectly cut diamond, the facets are so carefully arranged that
entering rays of light jump from wall to wall of this transparent
enclosure and emerge again at the very point of entry. Cleverly arranged
mirrors sending a ray of light from one to all the others and back again
to the first will produce the same effect. Lights entering a diamond are
reflected, refracted and dispersed. The dispersion of a ray of white
light separates it into its component color rays. These are the spectrum
colors often seen radiating from a diamond. Placing a diamond in the
sun’s rays and holding a sheet of white paper at the proper angle to
catch the reflections from the stone clearly shows these colors.
[Illustration: MODERN AMERICAN CUT DIAMONDS]
Brilliancy is often said to be the most important quality of a diamond,
but that is not true. Yellow diamonds are more flashingly brilliant than
white stones that cost much more. In each color grade, greater
brilliance determines higher value over stones of the same color grade
with less brilliancy. The diamond is the hardest known substance in the
world, cutting and grinding all other known hard things, but itself only
cut and ground by its mates.
Because of their hardness, diamonds worn by many previous generations
remain as brilliant as they were in the beginning and they will continue
so to the end of time.
No other thing can scratch or mar the polished facets and sharp corners
of the diamond. It is the hardest of all known things. While all
diamonds are of practically the same hardness, this is not, however,
absolutely true, as stones from wet diggings or rivers are slightly
harder than those from dry diggings. All diamonds are infusible and
unaffected by acids or alkali. The heat of a burning building will not
affect them, they can be raked from the ashes uninjured and can only be
burned in oxygen under a scientifically produced intense heat of 4000°
F. While the hardest known thing, the diamond is brittle and can be
crushed to a powder. It is the only absolutely pure gem, being composed
of crystallized carbon--all others are composed of two or more elements.
* * * * *
The term “Shibboleth” has come to mean a countersign or password of a
secret society since the Biblical days, when the Ephraimites, who had
been routed by Jephthah, tried to pass the Jordan. They were made to
pronounce the word “Shibboleth” and were easily detected as enemies when
they pronounced it “Sibboleth.”
Why do We Get Hungry?
Hunger is a sensation partly arising in the stomach, since it may be
relieved temporarily by the introduction into the stomach of material
which is incapable of yielding any nutriment to the body. It may be due
to a condition of fulness of the vessels of the stomach, relieved by any
stimulus which, acting on the lining membrane, induces a flow of fluid
from the glands. But it also arises from a condition of the system,
since the introduction of nutriment into the blood, apart altogether
from the stomach, will relieve it. This is also evident from the fact
that hunger may be experienced even when the stomach is full of food,
and when food is supplied in abundance, if some disease prevents the
absorption of the nourishment, or quickly drains it from the blood.
Hunger may be partially allayed by sleep or by the use of narcotics,
tobacco and alcohol, all of which tend to diminish the disintegration of
tissues.