a trend creation |
Diamond
Introduction
The mere mention of the
word
fills the
mind with a multitude of concepts and images. Diamond is a mineral, a
natural
crystalline substance, and the transparent form of pure carbon. Diamond
is
something superb, the peerless "king of gems" that glitters, dazzles,
and symbolizes purity and strength. Diamond is for engagement and the
75th
wedding anniversary, for a commitment to never-ending love. Diamond is
indomitable, the hardest surface known. Diamond is exotic, formed in
Earth's
interior and shot to the surface by extraordinary volcanoes. A diamond
is
likely the oldest thing you will ever own, probably 3 billion years in
age,
fully two-thirds the age of the Earth. Diamond is a strategic and
high-tech
super material for our technological society.
Owning a diamond
has always
meant possessing something of great beauty and lasting value. Diamonds
are
certainly the most precious of all nature's creations. Their fiery
brilliance
captures our hearts as the eternal symbol of love. However, if you're
like most
people, you probably know very little about diamonds. Diamond is the
name given
to the crystallized form of the element Carbon. Diamonds were formed
under
extreme heat and pressure at our Earth's core. They traveled to the
surface
through volcanic pipelines known as kimberlitic during the Earth's
formation.
Due to their unique physical properties, diamonds have been sought
after by
Kings and nobles throughout eons of time. Diamond is a form of carbon
that is
crystallized in the crystal system of highest symmetry known as the
cubic
system. It possesses a hardness far surpassing that of any other
substance
known in nature. The durability of a gem depends on both its hardness
and
toughness. Diamond although highest on the scale of hardness, is
cleaved before
forming the consumable shapes like other gems. Cleavage is one of the
tendencies of a diamond to split in certain directions where the carbon
atoms
are furthest apart. Diamonds have a very high degree of transparency,
refractivity and dispersion or 'fire' which gives rise to cut diamonds
to a
high degree of brilliancy and a display of prismatic colors. A
diamond's fiery
brilliance makes it cherished above all other gemstones by the majority
of
people. Diamonds occupy a position of incomparable demand.
Today diamond
symbolizes
wealth, durability, status and peerless quality. Across time and
Cultures,
diamond has also been associated with Invulnerability, lightning,
magic,
healing, protection and poisoning. In unraveling the history and
associations
of diamond, we also need to know the history of the words attached to
it:
Did the
words
used by the
ancient Indians or Greeks signify the same thing they do today, or
something
very different?
"Diamond" comes
from the Greek adman, transliterated as "adamao," "I tame"
or "I subdue." The adjective "agamas" was used to describe
the hardest substance known, and eventually became synonymous with
diamond. It
is difficult to determine at what point in history the hardest known
substance
become diamond. "Agamas" may have previously referred to the next
hardest mineral, corundum -- the gem variety is sapphire -- or to
something
else altogether. Tracing the history of diamond is complicated by this
problem
with names.
For over 2000
years,
diamonds were found only as eroded crystals in river gravel. Until
1725,
Further
exploration in the
The
Virtues of Diamond:
A diamond
octahedron was highly valued: "He who, having pure body, always carries
a
diamond with sharp points, without blemish, free from all faults; that
one, as
long as he lives, knows each day will bear some things: happiness,
prosperity,
children, riches, grain, cows and meat. He who wears [such] a diamond
will see
dangers recede from him whether he be threatened by serpents, fire,
poison,
sickness, thieves, flood or evil spirits."
The
Finest Diamond: A diamond that
flashed rainbow colors was best: "Even if it has blunt points, if it
has a
speck, a crack, the diamond that has the reflection of the rainbow
procures
wealth, grain and sons. The king who carries, so it is said, a
beautiful
diamond with glittering flashes has a force that triumphs over all
other powers
and becomes master of all neighboring lands." Rainbow disperse color
from
a diamond octahedron takes overall precedence and the finest colorless
diamonds, transparent octahedral with rainbow reflections, are reserved
for
kings.
The
Hardness of Diamond: Diamond's
supreme hardness was recognized: "The gems and the metals that exist on
earth are all scratched by the diamond: the diamond is not (scratched)
by them.
A noble substance scratches that which is noble and that which is not;
the
diamond scratches even the ruby. The diamond can scratches, but
diamonds not
scratched by any."
Origins
in
Diamonds were
discovered in
Knowledge of
diamond and the
origin of its many conations start in
Writings: The earliest
known reference to diamond is a
Sanskrit manuscript, the Arthasastra ("The Lesson of Profit") by
Kautiliya, a minister to Chandragupta of the Mauryan dynasty in
northern
Archaeology: No diamonds have
been found in ancient sites, but
holes in ancient beads show diamond's "footprint" cylindrical holes
with conspicuous concentric grooves left by a twin-diamond drill. The
holes are
unlike the marks of any other modern or ancient drilling technique -- a
signature of this diamond technology. Beads from sites in Sri Lanka,
India, Thailand,
Yemen and Egypt show the marks of diamond drills prior to 700 CE and as
early
as the 4th century BCE in Yemen.
Indian
Production:
While Mumbai is the heart of the diamond trade, the soul is provided by the neighbouring state of Gujarat in west India, where most of India's diamond processing takes place. Enterprising dealers from Palanpur in Gujarat have steadily risen to such prominence that they constitute arguably the most influential group in the world diamond trade today. (20th Dec. 2004)
Where
does
Diamonds Come?
Experiments and the high density of diamonds tell us that they crystallize at very high pressures. In nature this means that diamonds are created by geologic processes at great depth within Earth, generally more than 150 kilometers down, in a region beneath the crust known as the mantle. Other processes, explored later in this exhibition, bring diamonds to where people can find them.
The three
concentric layers
-- the core, mantle, and crust -- formed within a few hundred million
years of
Earth's coalescence 4.5 billion years ago. The core is primarily an
iron-nickel
alloy and makes up a large fraction of the mass of Earth. The vast
mantle is
sandwiched between the core and the thin crust and is composed
predominantly of
magnesium and iron silicate minerals. Our planet's crust is a thin,
rocky skin.
Diamonds can form in most of Earth's interior but not near its surface,
where
graphite is the stable form of carbon. Indeed, diamonds only survive at
Earth's
surface because great heat is required to break down the diamond
structure.
What is
Diamonds?
It is perhaps
difficult to
believe that diamond, like graphite and charcoal, is a form of carbon.
Diamond
crystallizes in cubic form crystals, at enormous pressures and high
temperatures over the course of millions of years. The process has been
imitated under laboratory conditions and then applied industrially to
create
"artificial diamonds". These have proven to be mainly of either
industrial, plain quality or very small. The diamond's exceptional
properties
arise from the crystal structure, in which the bonding between the
carbon atoms
is immensely strong and uniform. Much diamond occurs as well-formed
crystals,
most commonly as octahedral (eight-sided) crystal.
Diamonds
are blessed with three extraordinary qualities:
First, a diamond
possesses unique powers of light
reflection. When properly cut, it gathers light within itself,
reflecting it
back in a shower of fire and brilliance.
Second, it is the only
gem mineral composed of a single,
unadulterated element, making it the purest of earth's gemstones.
Thirdly, it is the
hardest transparent substance known to
man. Steel, for example, of which most machine tools are made, cannot
cut
diamond. The only material that can cut diamond is ...another diamond!
The
industry uses, therefore, for that purpose, "industrial grade",
usually black-color diamonds.
Diamond:
Vital Statistics
Composition: C
(carbon)
Crystallographic
Class: Cubic --
hex octahedral (highest of the symmetries)
Space Group:
Fd3m -- a = 3.57 A (cell edge)
Common Forms
{indices}: F
Octahedron {111}, cube {100}, dodecahedron
{110} rounded variations
Twins:
Spinal-law common, yielding the flat triangular "macle"
Hardness: 10
Moths' scale, 56-115 Knops hardness number (GPa), 10,000 Brooks
identical
scale; octahedral face hardest, cube face softest
Cleavage:
Excellent parallel to octahedron face -- {111}
Density:
3.51 g/cm3 (or specific gravity =3.51)
Luster:
Adamantine (diamond provides the definition for this kind of luster)
Colors:
Colorless, yellow, blue, and many others
Refractive Index:
2.4175 (in the yellow light of a sodium lamp)
Dispersion:
Large (0.044), leading to rainbow colors on refraction
Optical
Transmission:
Transparent over broad spectrum of the
electromagnetic spectrum; an excellent material for optical windows
Thermal
Conductivity:
Superb -- 5-25 Watts/centimeter-degrees C (at 300
K); 4 times greater than copper, an excellent thermal conductor
Electrical
Conductivity: 0
to ~ 100 ohm-cm (resistively at 300 K) -- an
insulator
What is the
Carbon?
Most diamonds
consist of
primeval carbon from Earth's mantle, but those from ecologists probably
contain
carbon recycled from the ocean crust by plate tectonics -- the carbon
of
microorganisms.
How do we
know
Carbon?
Carbon atoms occur in three different masses, or isotopes. Unlike high-temperature processes in deep Earth, low- temperature, biological processes, such as photosynthesis, are sensitive to the differences in mass, and actively sort different carbon isotopes. Thus, the ratios of carbon isotopes in organic materials--plants, animals, and shells -- vary, and differ from those in the carrbon dioxide of the atmosphere and the oceans. Geochemists "read" the carbon isotopes in samples to interpret nature's record. Virtually all carbon atoms, the ones in a diamond or a tree or you, came from the stars. Particularly at Earth's surface, the proportions of 12C and 13C (the carbon isotopes of mass 12 and 13) are redistributed. Expressed as simple numbers in 13C notation -- in which larger numbers mean more 13C -- organic carbon has large negative values, average Earth has a mildly negative value, and the carbon in shells is near zero.
Glossary
Blemish: Blemish the
surface of a diamond on flaw or
abrasion.
Brilliance: Cutting a
diamond to the correct proportions
maximizes its brilliance, defined as white light reflected up through
the
stone’s surface.
Brilliant
Cut: A brilliant cut utilizes 58 facets. It can be heart
shaped, pear, oval, radiant or round.
Carat: The unit of
weight, which diamonds are measured.
One carat equals one-fifth of a gram.
Clarity: A grade that
indicates how many inclusions a
diamond has. The scale ranges from Flawless (FL), which means that the
diamond
has no flaws inside or on its surface, to Severely Included (I3),
meaning a
diamond has numerous flaws that can be seen without magnification.
Cloud: Cloud is a group
of small inclusions inside a
diamond.
Color: Color is a grade
that indicates the color of the
stone. The scale ranges from D, completely colorless, to Z, which
refers to an
easily noticed yellow tone. The higher scale, the more distinct the
stone’s
yellow or brown cast.
Culet: Culet can be
seen as a miniscule focal point where
the pavilion’s facets converge. Facet on the bottom tip of the diamond
is culet.
A diamond with no culet has a pointed tip. A diamond with a small to
large
culet has a flat surface at the tip. Culets can prevent chipping, but
are less
desirable when of the medium to large range. A diamond with a medium to
large
culet will appear to have a hole in the bottom when looking down on the
stone,
through the table.
Cut: Refers to both
the shape of a stone (heart-shaped,
oval, round, etc.) and the make (the precise proportions that result
from the
diamond’s cut). The stone’s make determines how much sparkle it
reflects more
than any other factor.
Cut,
Ideal: Refers to perfectly proportion, round diamonds that
receive high grades on symmetry and polish. The finest craftsmanship
enhances
the beauty of these stones.
Cut,
Very Good: A diamond with this cut adheres to strict
requirements for uniform proportions that make the most of the stone’s
brilliance and fire.
Cut,
Good: This diamond’s cut displays proportions that are
acceptable but not perfect. It has very good fire and brilliance
Cut,
Fair: This cut makes the most of the diamond’s weight,
which often results in less fire and brilliance. A diamond with this
cut is
less expensive than a diamond with a Good or Very Good cut, but it will
not
sparkle nearly as much.
Cut,
Poor: Poorly cut diamonds appear lifeless. We do not
recommend stones with this cut.
Depth: Depth refers to
the height of a diamond from the
culet to the table. The depth percentage listed on the certification
indicates
the height of the diamond relative to the width measurement (height
value,
width value). A diamond, which is too shallow or too deep, will
disperse light
through the sides or the bottom instead of the top facet.
Depth
Percentage
(%): The depth percentage,
divided by the width of the diamond, mitigates the brilliance and fire
in the
stone. A diamond lacking sparkle probably has a depth percentage that
is too
shallow or too deep.
Eye-clean: Refers to a
stone with no flaws visible to the
naked eye.
Facet: The diamond’s
table polished surfaces. A round
brilliant diamond possesses 58 facets.
Fire: The Fire of the
color light reflects from the
surface of the diamond
Fluorescence: A glow, often
bluish in hue, that emanates from
some diamonds when they’re bathed in ultraviolet light. Avoid high
degrees of
fluorescence; faint to medium fluorescence, however, usually does not
change
the diamond’s appearance. The effect of fluorescence depends on the
combination
of the color of the stone in question and the strength of the
fluorescence.
Faint fluorescence has very little effect on a stone of any color.
Medium blue
fluorescence and strong blue fluorescence can have a positive effect on
stones
of low color (J or worse). The fluorescence actually has the effect of
making
the stone look closer to near colorless. On stones of high color (D-G),
strong
or medium blue fluorescence can make the stone look milky instead of
colorless
or near colorless
Girdle: A diamond’s
girdle is a thin band that traces the
stone’s diameter. The girdle is the narrow belt around the stone, which
divides
the top portion of the diamond (crown) from the bottom portion of the
diamond
(pavilion). Girdle is usually expressed as a range, indicating that it
may vary
from one part of the stone to another. If a girdle has small, flat,
polished
surfaces on it, it is referred to as "faceted".
Inclusion: Inclusions, or
tiny flaws, are created during the
diamond’s formation underground. They are fractures, mineral traces,
and other
imperfections that contribute to the stone’s uniqueness.
Make: Make of the
stone’s proportions as determined by
its cut. The better the make, the more fire and brilliance in the
diamond. A
worse make results in the stone’s inability to reflect light well,
which means
it will sparkle less.
Measurements: Measurements are
calculated to the nearest
hundredth millimeter and are usually written in this format: length x
width x
height
Pavilion: The diamond’s
bottom area is just under the girdle
to the culet.
Point: The point
measurement of the weight is equivalent
to one of the 100th of a carat. (50 points = 0.50 carat)
Polish: A grade assigned
to the stone’s outer finish. The
grading scale ranges from excellent to poor. Polish refers to the
external
finish of the facets. An excellent polish reflects the quality of the
work the
diamond cutter has put into the stone.
Symmetry: A grade assigned
to the cut’s overall uniformity.
The grading scale ranges from excellent to poor. Graded according to
how
precisely the facets are aligned (i.e., the top of the facet should
mirror the
bottom of the facet). A facet that does not have symmetrical sides will
negatively affect how light reflects from the stone.
Table: The largest flat
surface on the top (crown) of the
diamond is table. The table percentage refers to how much of the total
width is
occupied by the table. A table that is either too large or too small
will
negatively affect how Light reflects up from the surface of the stone.
Table
Percentage
(%): The table’s width divided
by the diamond’s diameter. A proper table percentage is necessary for a
diamond
to sparkle. A too-low or too-high table percentage will make the stone
duller.
4Cs
Description:
Many people are
confused
about how diamonds are priced. The best Explanation is that
asking for
the
price of a diamond is like asking for price of a house. A real estate
agent
can’t quote you a price for a house without knowing its size,
condition,
location, etc. This process is the same one used when buying a diamond.
A
diamond’s beauty, rarity, and price depend on the interplay of all the
4Cs.
4C's of Diamond
Quality
Diamonds are graded by four characteristics: cut, color, clarity, and
carat
(weight). All four of these properties determine how much a diamond is
worth.
The 4Cs are used throughout the world to classify the rarity of
diamonds. Diamonds
with the combination of the highest 4Cs ratings are more rare,
consequently and
more expensive. All this 4Cs are important than another in terms of its
beauty
and it is important to note that each of the 4Cs will not diminish in
value
over time. Once you have established those 4Cs characteristics that are
most
important to you, a jeweler can then begin to show you various options
with
quoted prices. The Diamond Picture is a framework to help you compare
diamonds.
While all diamonds are precious, those closest to the best combination
of cut,
color, clarity, and carat (weight) are the earth's rare and most
valuable.
Cut |
Color |
Clarity |
Carat |