Academy of JEWELRY Design
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+91-9840689781
Chennai Jewellery Academy Design School <
chennai.jewellerydesignschool@gmail.com>
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Greams Road
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Chennai - 600006
seshu.gopal@jewelrydesignacademy.com
- What is a diamond?
- Where do diamonds come from?
- How is a diamond cut?
- What is an "Ideal Cut"?
- How does a diamond get from the mines to the stores?
- Is a diamond a good investment?
- What is the difference between a "certified diamond" and a "non-certified diamond"?
- Is it safe to receive a diamond in the mail?
-
-
A
diamond is a crystal made up entirely of carbon atoms that are arranged
in an isometric, or cubic, matrix. A cubic crystal arrangement is one
in which the crystal essentially expands outward at the same rate in all
directions during its initial growth; the ideal result, when the
crystal forms without any interference, is a pure and perfectly formed
octahedral shape. However, most diamond crystals encounter varying heat
or pressure, other elements, or even other diamond crystals during their
growth, and this can alter their form somewhat. The resulting form and
characteristics of the crystal, once it emerges from the earth, help to
determine what shape, color and clarity the polished gem will have.
The
combination of diamond's molecular composition and its crystal
structure is what makes it so unique and gives it all the qualities that
we think of when we think of a diamond.
Consider this: The graphite
that you commonly find in pencils is also made of pure carbon, but
because the carbon atoms are arranged differently, the result is a soft
gray-black substance that is very unlike hard, colorless diamond. And
iron pyrite (known more commonly as "fool's gold") grows in an isometric
arrangement, but because it is not made of pure carbon, it also lacks
the spectacular qualities of diamond.
The
unique characteristics of diamond go far beyond what you can see with
your eye. In addition to their superior brilliance and dispersion,
diamonds are the hardest natural substance on earth.
Diamond
rates a 10 on the Mohs scale of hardness, which means that it is
extremely resistant to scratches; it is several times harder than the
next-hardest substance, corundum, which is more commonly known as ruby
and sapphire.
Diamonds
are also very tough, meaning that they do not easily break, chip or
crack. And even more interestingly, they are extremely resistant to heat
and chemicals: it would take a temperature of at least 720° Celsius in
air, or 850° Celsius in a vacuum, to burn a diamond; and sulphuric and
hydrochloric acids, which are capable of completely dissolving the skin
and bones of a person, have no effect at all on diamonds (in fact, these
acids are actually used to clean the oil and dust off polished diamonds
after they have been cut).
This question had been unanswered till the end of the seventeenth century.
Even the relationship to carbon was suspected.
In
1694, two Italian academicians had done an experiment on diamond in
Florence. They set up a large burning glass focused on a small diamond
and saw it “cracked, coruscate and finally disappear”, leaving a minute
quantity of blue ash. But it was the French physicist Babinet, who
proved beyond reasonable doublet that a diamond was carbon in
exceptionally pure form.
One
of Lavoisier’s most celebrated experiments was to place a diamond in a
bell jar filled with oxygen which rested in a basin containing mercury.
The rays of the sun were then focused on the diamond by means of a large
burning glass. After the diamond had been consumed, the bell jar was
found to contain great quantities of carbonic acid, indicating to
Lavoisier that the diamond was composed of carbon. Later experiments by
Humphry Davy in England prompted him to conclude that the diamond was
composed of carbon and nothing else, a view that was first contradicted
in 1841 by Dumas and Strass whose numerous experiments revealed minute
traces of other elements notably nitrogen and aluminum. It is these
slight impurities that deform the perfect crystalline structure of the
ideal diamond and can have a marked effect on the physical properties of
a stone.
It
would be an exaggeration to say that not much more is known about the
origin of diamonds today, more than two thousand years ago when they
were believed to be the splinters of stars. Nevertheless, it is true
that there is still no unanimity among geologists about exactly how and
where diamond is formed. As late as the nineteenth century, theories
about the origin of diamonds had been shaped by the fact that the stones
had always been found on or very close to the surface, either in
riverbeds or in the beds of the rivers that had dried up ages ago. Even
as late as 1869 the Gentlemen’s Magazine of London reported that a
“continental experimentalist” had declared that the intense cold of
stellar space disassociated and crystallized carbon from “masses of
meteoric nature coursing through space” and caused diamonds to fall from
the sky. The editor went on to comment that “the location of diamonds
upon the earth agrees much better with the hypothesis of a sky source
than an earth source” and that “those cope specimens now attracting so
much attention are found on the surface of the ground only it is of no
use to dig for them”, still the “continental experimentalist” may well
have a point. Diamonds have been found in meteor craters at Novo Urei in
south-eastern Russia and at Canyon Diablo in Arizona; although most
scientists believe they were created by the heat and pressure of impact
and not carried to earth in the meteors.
It
was not until the discovery of the “dry diggings” at Kimberley in 1870,
coupled with the determination of the miners to excavate every inch of
their dearly bought claims that it became clear that diamonds came from
below and not from above. It was also clear that diamond was invariably
associated with one particular type of rock and that this rock was only
to be found in clearly delineated areas. Since the rock and the diamonds
persisted at depth, it was soon suggested that these “pipes” were
volcanic in nature and that diamonds had been formed out of carbon under
intense heat and pressure deep in the bowels of the earth. They had
been forced toward the surface when those long extinct volcanoes had
erupted millions of years ago. This strange diamond bearing rock, soon
to be called Kimberlite was assumed to be nothing more than solidified
lava. But as mining progressed at Kimberley it was discovered that the
pipes were not great volcanic funnels plunging into the earth’s core.
A
great deal has since been learned from the making of synthetic diamonds
and perhaps the most widely accepted current theory is that since
diamond forms at pressures and temperatures between 0.5 million pounds
per square inch, the formation must have taken place at depths of at
least 120 miles, chemical studies pointed to the ultra basic rock
peridotite in its molten form as the most likely to have provided the
right conditions for the creation of diamond from carbon. The molten of
crystallization is assumed to have been long and slow and the theory
goes that conditions remained stable for a considerable period as a
result of the pressure of carbon dioxide gas below became too great, the
balance was changed and the diamond bearing magma was driven
explosively towards the surface. On the way, it picked up other rocks
and minerals forming itself into the “geological plum pudding” that we
now call Kimberlite, eventually erupting through the surface of the
earth and solidifying.
Diamonds
are made up of pure carbon atoms that exist deep in the ground, exposed
to intense heat and pressure over billions of years. Over time, this
pressure builds up and forces the diamonds and rocks up toward the
surface in a volcanic-like explosion. The explosion creates a very deep,
wide hole called a "pipe" into which most of the diamonds settle; these
deposits of diamonds are known as primary deposits. Other diamonds are
washed away by water or erosion, and often settle into the coastal
waters of nearby bodies of water; these are alluvial deposits. These
deposits occur in many places around the globe; however, the largest
commercial deposits exist in Angola, Australia, Botswana, Namibia, South
Africa, Russia and Zaire, which produce 80% of the world's diamonds.
Walking
through the aisle of a jewelry store, you may not think diamonds are
especially rare. But consider this: 250 tons (500,000 pounds) of ore
must be mined and processed to produce just one carat of rough diamond.
Since a rough diamond typically loses 40% to 60% of its weight when cut,
that means that all these efforts are necessary to produce just one of
the .50 carat polished diamonds you find in the store's display
counters. When you also consider the fact that only about one quarter of
all rough diamonds are actually suitable for gem cutting, you can begin
to appreciate the rarity and uniqueness of each diamond.
A
quick, fun fact: The first diamond deposits were brought to the surface
of the earth approximately 2.5 billion years ago. The most recent
deposits are roughly 50 million years old. Your diamond is a truly
unique piece of history.
A
newly mined rough diamond looks more like a piece of glass washed up on
the beach than like the polished gems sold in jewelry stores. Bringing
out their beauty requires the skill and art of a trained diamond cutter.
While
incredibly precise, computerized machinery is now used in some parts of
the cutting process for some diamonds, most of the work is still
performed by hand using exacting and meticulous techniques passed down
over the generations.
As
a first step, cleaving or sawing is often used to separate the original
rough into smaller, more workable pieces that will each eventually
become an individual polished gem. Next, bruting grinds away the edges,
providing the outline shape (for example, heart, oval or round) for the
gem. Faceting is then done in two steps: during blocking, the table,
culet, bezel and pavilion main facets are cut; afterward, the star,
upper girdle and lower girdle facets are added.
Once the fully
faceted diamond has been inspected and improved, it is boiled in
hydrochloric and sulfuric acids to remove dust and oil. The diamond is
then considered a finished, polished gem.
What is an "Ideal Cut"?
The
"Ideal Cut" is a cut based on a specific set of proportions for a round
brilliant diamond proposed by gem cutter Marcel Tolkowsky in 1919.
While Tolkowsky's original theories presented only one particular
combination of proportions for creating the best balance of brilliance
and dispersion, today the American Gemological Society recognizes any
diamond falling within a narrow range of proportions and finish quality
as being an "Ideal Cut" (also called an "AGS 0" or "AGS triple zero").
How does a diamond get from the mines to the stores ?
Finding
the rough diamonds is only the first step. Once diamonds have been
mined and processed out of the 'overburden' (that is, the kimberlite
rocks in which they are imbedded), the rough crystals are sorted and
categorized according to their size, color, shape and other
characteristics. At this point, a diamond can follow one of two routes.
The
most common route is through the channels of DeBeers' Central Selling
Organization (CSO). Many people are familiar with DeBeers mainly because
of their advertisements and commercials and because of the famous motto
that they coined in the early half of the 20th century: "A Diamond is
Forever."
While DeBeers' market influence has decreased somewhat over
the last few years, they still control the majority of the world's
diamond production (an estimated 30% to 40% of annual diamond
production).
The
purchasing arm of the CSO not only buys diamonds from member mines
around the world; it also finances mining technology for governments
which do not have the means to mine their own deposits. Most of what is
bought through the CSO is sent to London to be offered to buyers through
DeBeers marketing arm, the Diamond Trading Corporation (DTC). The DTC
holds ten week-long selling sessions called 'sights' each year. These
sights are by invitation only, and only a handful of diamond
manufacturers from around the world (called 'sightholders') are allowed
to attend. These sightholders may chose to cut the rough diamonds they
buy themselves, or they may chose to sell some of the rough diamonds to
smaller manufacturers. These smaller manufacturers cut the rough
diamonds and sell the polished gems either to jewelry manufacturers (who
set the diamonds into finished pieces of jewelry and then sell the
jewelry to jewelry retailers), or to diamond wholesalers (who then, in
turn, sell the diamonds to diamond retailers).
In
the less common route from mine to market, some independent miners
elect not to sell their mine production to the DeBeers cartel. Instead,
they offer newly mined diamonds directly to other world buyers. These
buyers, in turn, may chose to cut and sell the diamonds themselves, or
pass the diamonds along within the industry in a manner similar to that
described above.
The answer depends on whether you are investing in the diamond itself, or in what a diamond represents.
Diamond
prices have been steadily increasing for the past 20 years, and
diamonds tend to hold their value. Given this, it is extremely unlikely
that diamonds will ever entirely lose their value, in spite of how the
market may change in the future. However, no one can predict, with
absolute certainty, which way the market will swing and, in general, we
do not recommend buying up high-quality diamonds as a main part of a
financial/retirement plan.
On the other hand, if you are looking for a
source of beauty and a symbol of eternity and everlasting love, there
are few objects you can choose that will surpass a diamond's perfection.
Diamonds have inflamed man's passions since the first moment at which
they were discovered, and their power over our emotions and desires has
only grown since then. As a timeless and beautiful gift to yourself or
as an emblem of your commitment to another, a diamond is an excellent
investment.
What is the difference between a "certified diamond" and a "non-certified diamond"?
There
is no physical difference between a diamond that is certified and one
that is not. A certificate does not change the nature of a diamond in
any way. The difference between a certified and an uncertified diamond
is that, with the certified diamond, you have tangible, legal assurances
as to the particular nature and quality of the diamond you are
purchasing.
A
certified diamond comes with a diamond grading report guaranteed by an
accredited gem lab. This report assures the customer that the diamond is
independently recognized as possessing all the qualities specified by
that report. All the diamonds featured in the Diamond Store on our site
are certified by either GIA or AGS. When you buy a certified diamond,
you are getting a diamond with beauty and pedigree.
On
the other hand, an uncertified diamond has is not accompanied by a
diamond grading report, and therefore its stated quality is based only
on the word of the seller.
An
uncertified diamond is not necessarily a bad diamond; certainly, it can
be as beautiful as its certified counterpart. However, we encourage our
customers to buy certified diamonds for the following reasons:
Shopping
for certified diamonds allows you to make an informed choice about your
selections, and to comparison shop. You can compare one diamond with a
particular weight and quality with other diamonds of similar weight and
quality to determine which is the better value. With uncertified
diamonds, it is difficult to determine whether the quality assessments
of one jeweler will be as stringent and precise as the judgments of
other jewelers; that is, not all jewelers may agree about the quality of
an uncertified diamond.
A
diamond grading report adds value to a diamond. The quality assessments
made by independent labs, such as GIA or AGS, are recognized worldwide.
These quality assessments are used by appraisers to determine the
insurance or replacement value of your diamond. If you purchase an
uncertified diamond, there is no guarantee that the appraiser will
appraise your diamond at the same level at which the jeweler who sold it
to you did. A quick note on how reports from various independent labs
compare with one another: GIA and AGS are considered the industry
leaders, and the final word on gem quality, among diamond dealers
worldwide. While plenty of other independent labs exist, some are a bit
lax in their assessments of diamond quality and do not command the same
respect for consistency and quality of grading that GIA and AGS do. For
this reason, if you are in the market for a diamond, make an effort to
buy only GIA- or AGS-graded diamonds.
A
diamond grading report adds an increased comfort-level to your
purchase. Because the quality of your purchase has been independently
verified, you can feel assured that you have made a wise purchase and
that you have received exactly what you have paid for.
Is it safe to receive a diamond in the mail?
Yes
and no. It is safe if the diamond jeweler uses insured carriers (e.g.,
FedEx and UPS) to ship its packages and all shipments are insured for
the full value of their contents.
Before
buying a diamond online, find out what the store's policy is in case of
lost shipments. A professional diamond jeweler should have no objection
to providing either a replacement or a refund.
History:
The
story of the diamond begins in a remote era the world’s history, lost
in the mists of time. For untold ages the diamond lay hidden and
unregarded within the earth, until man at last recognized it as the most
precious of all nature’s creation and begins to use it for his own
delight and benefit. We will probably never know exactly when the first
diamonds were discovered. But we do know that from ancient time until
eighteenth century, India was the world’s sole supplier. Although it is
impossible to locate the first discovery, there are very early documents
that mention the diamond and perhaps explain why man showed such
special interest in it. Many histories maintain that the diamond has
been known since ancient times.
In
Greek literature from very early date the word adamas (which eventually
gave its name, via Latin adamus, adamantinus, to the diamond) is often
used in sense very close to that of yahalom, being similarly associated
with the idea of invincibility. The first known use of the word occurs
in the works of the poet. Hesiod, who lived in the eighth century B.C.
But nowhere in Hesiod, or in any other writing of that period, is the
term applied to a diamond or any other precious stone. For some eight
centuries the word adamas was applied exclusively to iron, to describe
its unbreakable quality. Not until the first century A.D. was the word
used as a noun, by that time, no doubt, designating a diamond. It
appears as such in the celebrated Roman encyclopedia, the natural
History of Pline the Elder.
India: The first Producer
It
is curious that in all the numerous, lengthy arguments among historians
over the origin of diamonds, discussion nearly always centers on the
countries that acquired the gems and never on the country that produce
them. From ancient times until Brazil entered the picture in the
eightieth century, India was the only significant diamond producing
country. Until the twentieth century, source for the study of diamonds
in India were largely unavailable. In 1905, however, an ancient Sanskrit
manuscript was discovered, the Artha Sastra of Kautilya, which may be
translated as “The Lesson of Profit”. This remarkable work is basic text
providing invaluable detail of the economic and legal history of India
in the fourth century B.C. Kautilya was the minister of King
Chandragupta Maurya and had helped put him on the throne of the kingdom
of Magdha. King Chandragupta, who ruled from about 320 to 298 B.C., was
the founder of the Maurya dynasty and may be called the first emperor of
India. We know of him also through the Greek Megasthenes, who lived at
his court until the discovery of the Artha Sastra, in fact, Megasthenes
was our sole source of information on this period. A careful reading of
Kautliya’s treatise reveals unquestionably that not only were diamonds
known in the fourth century B.C., but they were commodities in a very
active trade, were subject to regular taxation and customs duties, and
were one of the sources of the royal revenue.
Diamond Found:
The
first undoubted diamond were discovered in India and it was there that
the first systematic diamond mining was carried on Jean Baptiste
Tavernier, the celebrated French Jeweller and traveller in the East,
recorded intensive mining going on in the 1660’s at Kollur near Golconda
the legendary fortress city that lent its name to the entire mining
area and served as the headquarters of the Indian diamond trade.
It
was at Kollur that the most famous Indian diamond-The Kohinoor, The
Great Moghal and The Regent are said to have been found. Another
celebrated diamond mining area was further north at Panna and
neighbouring villages in the province of Bundelkhand. It is a strange
coincidence that the Brazilian diamonds were found just as the supply
from India was running down, and that even the Brazilian deposits were
nearly exhausted in their turn, huge supplies were discovered in South
Africa. It had long been thought possible that diamonds would be found
in South Africa. The early Boers were farmers not explorers and they had
little interest in geology that not leads them to fertile soil or
abundant water. It was not until thirty years later in 1866, that the
first known diamond was picked up.
Everyone
knew that diamonds came from India and more recently from Brazil and
they had forgotten the skepticism that had greeted the Brazilian finds
in the 18th century. The colonial secretary is to have taken the diamond
into Cape town., placed his hand upon it and said “Gentlemen, this is
the stone on which the future success of South Africa will be built.
How to choose the Perfect Diamond
Buying
a diamond is one of the most important decisions a couple will make.
Choosing the size and shape along with the style of the mounting are
important personal choices. Understanding the characteristics that
influence the brilliance, beauty and value of diamonds can make your
buying experience more enjoyable and more fulfilling. Diamonds are like
people—no two are ever exactly alike. Very subtle differences in the
internal and external characteristics of each stone, along with subtle
variations in color and cutting proportions, have a measurable effect on
the value of two diamonds which may appear to be similar. Start with a
good jeweler, one who’ll take the time to help you through the 4 Cs—cut,
color, clarity and carat weight. Understanding the language of diamonds
will put you more at ease in making your selection. The next step
should be obtaining a diamond certificate from a reputable independent
gemological laboratory. The certificate identifies and evaluates
specific characteristics that determine the value of the stone you
select.
The diamond business
has been redefined by branding and the fundamentals of advertising, public
relations, and marketing - all of which are geared to the downstream retail and
consumer jewelry markets with their unique customer segmentation features and
demographics. Online access to the multiple brand environment of the diamond
business including articles about Lev Leviev & Bulgari - May 2004, the Art
of Marketing and Branding Diamonds, and The Case of the Missing Icon - De Beers
LV.
Emerging Trends Downstream:
Emerging trends in the global diamond jewelry, fashion, and retailing sectors.
Antwerp World Diamond Center:
Approximately 1,500 diamond offices are located in Antwerp on Hoveniersstraat,
Schupstraat, Rijfstraat, and Pelikanstraat.
Natural
Diamonds:
The cumulative effect of branding can already be calculated and determined. The
next challenge facing the diamond business, trade, and industry is promoting
the importance of and supporting the integrity of natural diamonds (and their
sources of rough). Private companies, individual diamond exchanges, the DTC,
and the World Federation of Diamond Bourses have already started to address the
issue.
Brands:
Branded diamonds and jewelry are the hottest topics in the diamond trade today;
hearts and arrows, ideal cuts, round brilliants, squares, fancy shapes, fancy
colors, modified rounds and fancies, the Regent, Queen of Hearts, Hearts on
Fire, the Lazare Diamond, the Leo Diamond, Dream, Prince, Nakshatra,
PrincessPlus, Royal Asscher, Lily Cut, Crisscut, cushion cuts, Rand, Cushette,
Zales, Princessa, Flanders, Sirius, Tsarina, Lucida, Elara, Tycoon, Escada,
Ashoka, Vera Wang, the Regent, the Queen of Hearts, the Eighternity, the Web
Cut, and the Radiant Star to name but a few.
Mumbai India's Diamond Capital:
Hundreds of diamond offices are located in the general area of the Royal Opera
House near the Roxy Cinema, Mumbai.
Surat World's Major Diamond Cutting & Polishing Center:
Surat, is the major diamond manufacturing center. 8 out of 10 diamonds are cut
& polished in Surat.
Sightholders:
Branded diamonds and jewelry and other sightholder programs have the advantage
of support from De Beers and the DTC including a new trademark, the forevermark
program, the Diamond Promotion Service (DPS) worldwide, the Diamond Information
Centers, J. W. Thompson, and many other added value features and services.
Jewelry Trade Shows:
The favorite venues for launching a new line of diamond set jewellery or a new
branded diamond are the jewelry tradeshows worldwide, including the JCK, the JA
New York, the Couture Show, Centurion, Diamonds by JCK, and shows in Las Vegas,
Tucson, Mumbai, Tokyo, Bangkok, Basel, Hong Kong, and China.
Bourses:
Offices in diamond exchanges and cutting centers, worldwide including Hong
Kong, Antwerp, Ramat Gan, New York, Tokyo, India (Mumbai and Surat), Israel,
China, Canada, Russia, South Africa, Dubai, Shanghai, and Moscow trade in both
rough and polished diamonds.
Israel Diamond Exchange:
Approximately 1,200 diamond companies are located in the Shimshon, Maccabi,
Noam, and the Diamond Tower buildings.
Diamonds Luxury Marketing
Advertising has increased in luxury, business, travel, bridal, fashion, and
jewelry magazines including Elle, Maxim, Oprah, Town & Country, Vogue, W,
Robb Report, InStyle, and Vanity Fair to name but a few. The bridal market (and
the media devoted to it) is considered to be an easy entrance course into the
world of branding and brands, because the curriculum stays the same and the
class changes on a regular basis.
THE 4 Cs
Cut
Cut
actually means two things: the shape of the diamond (round, marquise,
pear, oval, heart, emerald, princess, radiant, etc.) and the proportions
of the stone. When a stone is cut to good proportions, light is
reflected from facet to facet, then dispersed through the top. The
better the cut, the greater the sparkle, brilliance and fire of the
stone.
Color
Most
diamonds look colorless. But there are subtle shade differences that
range from colorless to yellow/brown. Diamonds are graded on a color
scale that ranges from D (colorless) to Z (yellow/brown). Diamonds with
no hint of color at all are extremely rare and are therefore, most
valuable. Most gem quality stones appear to be colorless, but they
usually have at least a hint of color.
Clarity
Almost
all diamonds contain a combination of internal and external
characteristics called inclusions and blemishes. Normally, they are too
minute to be visible without powerful magnification. Some are even so
small they require great skill and time to locate. The number, type,
location, visibility and color of inclusions determines a diamond’s
clarity and may influence its value.
Carat Weight
Like
all precious stones, the weight or size of a diamond is measured in
carats. A one carat stone is equal in weight to one hundred smaller
units called “points.” Therefore, a fifty-point diamond, for example, is
the same as a half carat. Carat weight is the most obvious factor in
determining a diamond’s value, depending on the quality of its cut,
clarity and color.
Grading Colored Stones
Gemstones
are the most fascinating natural objects on earth. Ancient historical
records show that primitive peoples adorned themselves with gems and
believed that gems had magical powers. Some societies even used powered
gems for medicinal purposes! The classification of gems in ancient times
was mainly associated with color. In other words, all red stones were
once called "ruby," all green stones were called "emerald," and all blue
stones were called "sapphire." Today people wear gems for many
different reasons, including fashion, sentiment, and prestige. As gems
became associated with money, the need for accurate identification grew.
The
introduction of manmade gems and imitation materials in the 1800's
created an urgent need for experts who could separate the genuine from
the fake. The invention of the first cultured pearls and green-glass
emerald imitations in the early 1900's further created need for
gemological expertise. Today virtually all gemstones, including
diamonds, have a number of manmade counterparts and imitations.
The 4 C's of Colored Gemstones
Colored
stones are graded in a similar way to diamonds. Color, clarity, cut,
and carat weight are the main value factors. The difference is that
these factors are evaluated and weighted somewhat differently than in
diamonds. Diamonds are assigned very precise grades for color, clarity,
and cut. In colored stones, color is the main consideration. Unlike with
diamonds, a minor clarity difference rarely affects the price of
colored stones.
Color:
Color
in gemstones normally results from the presence of small amounts of
trace elements. Some of these coloring agents are an essential part of
the gem's composition, while some are introduced as an extra element
when the gem is forming in the earth. Regardless, these elements are
responsible for the amazing variety of colors we see in the many
different gemstones. Even diamonds appear in virtually all colors of the
rainbow. Generally, the more pure and intense the color, the more
desirable and more valuable the stone will be. Once again, a top color
is more important than a top clarity.
Clarity:
The
internal purity or clarity of a colored stone is secondary to the color
quality. Clarity characteristics are often a beautiful part of a
colored stone--and a key to identification. Collectors even value some
colored stones for unusual inclusion scenery. In fact, inclusions can
actually increase the desirability and value of certain colored stones.
They do this by creating what is called "phenomena." An example of
highly valued and beautiful phenomena in colored stones is the star
appearance in sapphires and rubies, which results from the presence of
intersecting "needles" of the mineral rutile. The cat's eye phenomena in
tiger-eye quartz is the result of a similar condition, except the
inclusions are lined up in a parallel manner. The value of certain
colored stones, however, can be diminished by the presence of
inclusions, when those inclusions are so numerous that they interfere
with the passage of light through the stone and make it look cloudy.
Cut and shape:
Colored
stones are cut into a wider variety of shapes and proportions than
diamonds are. Where the round brilliant-cut is most popular for
diamonds, other shapes are better suited to show off a colored stone's
beauty, such as oval, cushion, pear, marquise, emerald cut, cabochon,
mixed-cut, trapezoid, and tablet. Each cut is chosen to show off the
best color and preserve the most weight from a colored stone. Colored
stone proportions also differ radically from those of a well-cut
diamond. The bulk of a colored stone may be on the bottom where it has
the best chance of returning the most brilliance and best color to the
viewer. Certain colored gems look better in some cuts than in other. For
instance, the majority of fine quality emeralds are cut in the
traditional emerald cut shape. Opals are always cut with a smooth curved
top (en cabochon). Fine quality rubies and sapphires are normally cut
in oval or cushion shapes.
Carat weight:
The
weight of diamonds and colored stones is expressed in carats. One carat
consists of 100 "points" and is equal to 0.200 grams.
