|
Top Quality Diamonds
HOMEPAGE |
VIEW
OUR DIAMONDS |
COMPANY
-
There is no great mystery in HOW
TO BUY A DIAMOND. In the 10 minutes it takes to read the following
information, you can possess as much, if not more diamond knowledge than
your average diamond sales person.
Here are the factors that make up Cost
-
The following guide assumes
the Gemological Institute of America (G.I.A.) grading system. This is the
worlds most recognized system of evaluating a diamonds quality and value.
Each grade describes a different aspect of the diamond and it is only the
sum total of all these characteristics which will determine if the diamond
is a true gem or just a commercial grade.
CARAT
-
CARAT means weight (1 carat = 1/5 of a gram) A diamond weight is a very
important factor to its cost.
-
The term "carat " originated from the seeds of the carob tree. These carob seeds
are extremely uniform in eight and this made them the ideal weight unit for the
ancient gem traders. This weight (one carob seed) as later standardized to be 1
carat, or 1/5th of a gram, hence a five carat diamond equals 1 gram and 155.51
carats equal one ounce.
-
The one carat weight is then broken down into 100 equal parts called "points";
75 points equal 3/4 of a carat, 50 points equal 1/2 of a carat, etc. The
significance of the weight is like the other quality grades. Rarity, now
by virtue of the diamonds size and weight. Out of 250 tons of diamond ore
only a single one carat diamond of gem quality may be found. The value of
weight a 100 point (1 full carat) diamond of VS-1 clarity and G body color is
generally worth more than an identical VS-1, G color diamond with a weight of
.99 carats (less than a full carat). A one point difference in a diamond
can make a difference in value.
-
It is important to understand that the weight of a diamond and its physical size
are two different things. Even if the only difference between the two
diamonds is .01 carat. Take for example two (2) VS-1, G quality grade 1.00
carat diamonds to show the vast difference in value that the cut will make.
One of these diamonds could have the Ideal 6.5 millimeter diameter size one
would expect to see in for a 1.00 carat diamond. In the other example, the
second 1.00 carat diamond may have only a 5.5 millimeter diameter. Because
of this one millimeter diameter size difference, and yet the same carat weight,
the smaller diameter diamond would be worth somewhere around 20% less than the
Ideal cut diamond of the same weight and quality grade.
-
These value
differences will vary depending upon the size and quality grade of the diamond
you may be interested in. This leads us to the fourth quality grade which is the
diamonds cut. Every Diamond belongs in a weight grouping class for a range of
weight where the prices per carat for each Color and Clarity group combination
are listed. The main reason for this is obviously due to rarity in nature,
but current market conditions at any specific time plays a very important role.
Some sizes and shapes fall in and out of demand due to what is fashionable or
considered affordable in society. Because of this, some size groupings for
a given shape may have a higher demand and price per carat than one
expects, given its rarity in nature.
-
So to simplify, a diamond in
the 1 carat class (1.00-1.49) usually costs more per carat than a diamond less
than 1 carat in weight (0.90-0.99). A diamond that is 1 full carat in
size, has a higher demand, which causes it to be priced higher. The result
is rough stones that could possibly have been cut into beautiful smaller stones
are usually cut into not so beautiful 1 full carat stones to get into the higher
price range. There are other factors and trade-offs this is just a
simplified answer to the reason the cost per carat goes up as the size goes up.
COLOR
COLOR GRADING arbitrarily begins
with "D" to avoid confusion. "A", "B", and "C" are assumed to not
exist but there is room in the color range to allow for finding them.
With grades "A", "AA", or "AAA" how do you know which one is the
brightest white color? Diamonds are color graded by a gemologist
against a master set of colors.
-
-
D-Fare
the finest & brightest colorless diamonds, usually for the discriminating
customer who can afford the most beautiful and the rare.
-
G-H
are very white & bright face-up colorless diamonds that are not as
expensive, and when mounted in jewelry it is difficult to see the a difference
between these and the higher grades.
-
I-J
are are not quite as bright or have very slight hardly noticeable tint.
-
K-L have
a slight tint even the average person will begin to notice.
-
M
or Lower the color will be noticed.
Each grade can have
a 10-15% variance in it's price range for a given size group, down to M,
and then it changes again depending on the Hue & Color for the Fancy
Colored Diamonds.
Diamonds occur naturally in all spectral
colors, from red to blue, however the most commonly occurring colors are yellow
and brown. The amount of color a diamond possesses is graded by an alphabetical
scale D through Z. They began at D in case a whiter diamond was later found.
Color & Cut are the two factors that influence a diamond's beauty the most.
Color should reflect one's tastes and budget.
i.e.: You may be able to go with a higher color grade and lower clarity grade to
suit your taste and stay within budget.
Diamonds of a colorless grade
in the D-F range are much more valuable than diamonds in the L-P range
because of the rarity of these colorless diamonds. This is not to say that
the diamonds in the lower color range are not pretty, they can have just
as much brilliancy and sparkle but with a stronger color tone. The effects
of color to the cost of a diamond can be dramatic. Two diamonds of the
same weight, clarity , size and shape can have a cost difference of over
100% for the difference between an F body color to a J body color . Color
can only be graded accurately if the diamond is un-mounted or "loose" and
it is highly recommended that the diamond be independently certified for
its color as well as the other following quality grades. The color of your
diamond will be simply a matter of personal taste and if you don't like
the color - just plan to spend more money!
Another color factor to consider
is Fluorescence, properly called photo-luminescence. Fluorescence
is caused by a trace amount of the element boron found in the diamond.
It is activated by UV light. Fluorescence in a diamond is usually described on
a certificate (GIA, EGL, etc.) as None, Faint, Medium, Medium blue, Strong, Strong blue and Intense Blue.
Other colors of fluorescence do occur, yellow and white for example (try to avoid them), but it
is the blue we are most commonly involved with. In the old days people
used to come looking for the perfect "blue-white" diamond. The blue referred
to the fluorescence and the white to the diamonds body color. Some
people think diamonds exhibiting fluorescence is out of fashion, but Gems
and Gemology (put out by GIA) GIA states that typically fluorescence is
a plus in a diamond. Most people feel that fluorescence is beautiful and
rare in a diamond, so in a few years fluorescent diamonds may be back in
fashion and will demand a premium. If you want a diamond that exhibits
fluorescence be sure you examine it under all light conditions, especially
direct sunlight and a jewelers black light, since some fluorescent diamonds
will actually become hazy in the sunlight and others will glow in a black
light environment (including a dance floor) if the fluorescence is Intense
(and sometimes Strong). With Strong or Intense fluorescence I advise
you to fully examine the stone, each diamond will exhibit its own traits,
and in many cases these traits will have a positive effect, often causing
the diamond to have a little "extra life" in the sunlight. If you
are dealing with a diamond of D, E, or F color, fluorescence is usually
a negative since it won't make it look whiter, and may make it look a bit
hazy in sunlight. On the other hand, if you are dealing with a diamond
in G, H, I, J, or K color, fluorescence is normally a plus, and will whiten
the diamond one or more grades, thereby increasing the diamonds beauty
and desirability.
So to sum up, examine any diamond
with fluorescence under all light forms and make up YOUR mind for YOURSELF,
as to whether it is a plus or minus.
COLOR GRADING SCALES
| COLOR |
GIA* |
CIBJO* |
| COLORLESS |
D |
EXCEPTIONAL WHITE+ |
| E |
EXCEPTIONAL
WHITE |
| F |
RARE WHITE+ |
|
NEAR
COLORLESS |
G |
RARE WHITE |
| H |
WHITE |
| I |
VERY SLIGHTLY
TINTED WHITE |
| J |
SLIGHTLY
TINTED WHITE |
|
FAINT
YELLOW
to
FAINT BROWN |
K |
TINTED
WHITE |
| L |
| M |
TINTED
COLOR 1 |
|
VERY
LIGHT YELLOW
to
VERY LIGHT BROWN |
N |
TINTED
COLOR 2 |
| O |
| P |
| Q |
| R |
|
LIGHT
YELLOW
to
LIGHT BROWN |
S |
TINTED
COLOR 3 |
| T |
| U |
| V |
| W |
| X |
| Y |
| Z |
CHAMPAGNE
COGNAC
GREENISH
BROWNISH
YELLOW |
C+ |
FANCY
COLOR |
| LIGHT
FANCY |
CANARY
YELLOW
GREEN
BLUE
PURPLE
PINK
RED |
FANCY |
| FANCY
INTENSE |
| VIVID |
* GIA = Gemological Institute of America.
* CIBJO = Confederation Internationale de la Bijouterie,
Joaillsrie, Ortevrerie, des diamants, perles et pierres precieuses. |
Dollar Cost effects
of Fluorescence
| |
IF to VVS
grades |
VS to SI
grades |
I-1 to I-3 grades |
| D E F colors |
strong -10%
moderate -5%
weak -0% |
strong -5% to -10%
moderate 0% to -5%
weak -0% |
-0% |
| G H I J colors |
strong -5% to -10%
moderate -0% to -5%
weak -0% |
strong -0% to -5%
moderate -0%
weak -0% |
-0% |
| K L M colors |
strong -0 to -5%
moderate -0%
weak -0% |
strong -0%
moderate -0%
weak -0% |
-0% |
CLARITY
In plain terms clarity is simply how much "stuff" is inside
the diamond crystal. The less the "stuff" the more they cost. This again
because of rarity by lack of imperfection. Most all of the diamonds mined
have inclusions that are visible to the unaided eye. A typical retail
jeweler may sell a flawless clarity grade diamond once every 10 years,
maybe!
This scale ranges from F to I-3. This entire scale can be divided in half,
with diamonds that you can visually see the imperfections to the unaided
eye, and diamonds that require 10 power magnification to see the imperfections.
This division is at the I-1 clarity grade to the SI-2 clarity grade. The
I-3 clarity grade will generally contain enough imperfection to dramatically
reduce the amount of brilliancy and sparkle and should not be considered
for "fine jewelry". However there can even be a good , as well as bad I-2
or I-1 clarity grade diamond. As an example a good I-1 clarity grade diamond
would have an imperfection to the side which would be eye visible, however
after being set would be covered by a prong or other feature of the setting.
The less desirable I-1 clarity grade diamond would possess a very similar
inclusion however because of its location would not be able to be hidden.
An eye visible inclusion such as this would later prove to be a distraction
to
the beauty of the diamond. As with the color of the diamond , clarity is
very much personal taste and if you don’t like the number of imperfections
- just plan to spend more money!
CLARITY GRADING SCALES
| FL |
FLAWLESS
describes diamonds in which a gemologist
under favorable lighting conditions, cannot see any inclusions at ten power
magnification |
| IF |
INTERNALLY
FLAWLESS
describes diamonds which have no
internal characteristics observable under the the same conditions as (FL),
but which have minor surface blemishes that do not penetrate the stone. |
| VVS1 |
VERY,
VERY SLIGHTLY INCLUDED
describes diamonds that have very,
very small inclusions which are difficult for a gemologist to see at 10x
magnification. |
| VVS2 |
| VS1 |
VERY
SLIGHTLY INCLUDED
describes stones with very small
inclusions which can be difficult to observe with 10x magnification. Inclusions
are barely visible to the unaided eye, except on some larger stones or
large Emerald Cuts. |
| VS2 |
| SI1 |
SLIGHTLY
INCLUDED
describes stones with small inclusions
which are usually obvious when viewed with 10x magnification. Inclusions
are difficult to see with the unaided eye, except on larger stones or occasionally
with Emerald Cuts. |
| SI2 |
|
SI3
|
| I1 |
IMPERFECT
or PIQUE
describes stones with medium to
large inclusions (Piques) which are usually obvious to a gemologist with
the unaided eye. An I1 may have inclusions barely visible or located
to the side while an I2 will have numerous inclusions that may be centerally
located. |
| I2 |
| I3 |
CUT
The Cut is the most important characteristic
of a diamond. This factor determines how much light which enters the diamond
from above, then how much light will be reflected and refracted back out of the
gem to the eye of the observer. In other words how pretty the diamond can
be is decided by the cut. For the consumer it is fairly easy to determine
in general terms if a round brilliant cut diamond is well cut or proportioned.
The first and easiest characteristic to evaluate is to compare the diamonds
weight with the proper diameter size listed in the "Size to Weight Ratio Chart
"below. If a diamond has a 1.00 carat weight, then its proper diameter
size should be 6.5mm. This is the first and easiest characteristic to evaluate.
The rest of the characteristics, that are equally important, such as depth% and
table%, polish, symmetry can also easily be determined by comparing the
information in the tables below with the information provided on the certificate
of the diamond you are interested in.
|
Size to Weight Ratio
Chart
|
|
|
Generally if the size to weight ratio are cut correctly the entire bottom
side of the diamond is turned into a mirror. If the cut has been
poorly done even the highest quality grade diamond will look lifeless.
As an example, in the illustration below, lets assume that each of these
diamonds has a carat weight of 1.00 carats. The ideal cut diamond
model in the center will have a diameter measure of 6.5mm and will reflect
light to its optimum. The shallow cut model on the left will measure approx.
6.9mm+ and will "leak" light. The deep cut diamond on the right (the most
common cut) will also "leak" light and measure approx. 6.0mm and have the
physical size of a .80 carat diamond. These diamonds are not cut
this way because the cutter is unskilled, the cutter buys diamond just
like you, by the "carat" and it's his job to return the most carat weight
he can in a finished diamond.
.
|
Shallow Cut
|
Ideal Cut
|
Deep Cut
|
|
|
|
|
.
As in this illustration the "shallow cut" diamond has been cut too wide
and shallow for its weight and the light will escape out the back or pavilion
of the gem. In the "ideal cut" the diamond has been correctly cut and the
light entering the diamond will return to the eye. The "deep cut"
diamond has been cut too narrow and deep and again looses the light out
the pavilion. Diamonds are cut by the manufactures to yield the greatest
amount of carat weight from the rough, which they also buy by the carat.
It is therefore in the best interest of the cutter to cut for weight, not
for proportions. Consumers are generally not informed about cut and its
relation to value, cost, and beauty.
Now let's evaluate the cut. This includes the depth percentage, table
percentage, crown angles, crown height, girdle thickness, pavilion depth,
culet size, finish, symmetry and polish. All of these factors are
just a simple comparison of the data in the "Typical
Diamond Proportion Analysis Chart" below, and
with the laboratory certificate of the diamond you are interested in.
When ordering your diamond, we will be happy to explain all of these individual
quality grades in more detail. The Proportion Tables below will give
you the industry parameters for Round brilliant cut diamonds as well as
Marquise, Pear, Emerald, Princess and Ovals. Understanding the cut of a
diamond is very important, as two diamonds with the exact same quality
grades can have a 30% difference in cost because of the cut.
|
Typical Diamond
Proportion Analysis Chart
|
|
|
Proportions
for Round Brilliant cut diamonds
| Components |
AGS
000 |
Ideal
Proportions |
Near
Ideal Proportions |
| Total Depth |
61.6 - 62.7% |
60.1 - 62.8% |
57.0 - 65.0% |
| Table Diameter |
54.0 - 57.0% |
53.0 - 57.0% |
51.5 - 60.0% |
| Girdle Thickness |
thin to medium |
very thin to medium |
very thin to thick |
| Culet Size |
none |
none to medium |
none to sl. thick |
| Crown Angle |
34.5 degrees |
33 - 35 degrees |
30 - 35 degrees |
| Crown Height |
variable |
16.2% |
11.0 - 16.2% |
| Pavilion Angle |
40.75 degrees |
. |
. |
| Pavilion Depth |
43% |
43.1% |
41.5 - 45.5% |
| Symmetry |
excellent |
excellent to very good |
excellent to good |
| Finish |
excellent |
excellent to very good |
excellent to good |
Proportions for
Princess, Emerald and Radiant
| Components |
Ideal
Proportions |
Near
Ideal Proportions |
| Total Depth |
58.0 - 75.0% |
56.0 - 82.0% |
| Table Diameter |
57.0 - 78.0% |
54.0 - 85.0% |
| Girdle Thickness |
thin to thick |
thin to thick |
| Culet Size |
N/A |
N/A |
| Crown Angles |
30.0 - 37.5degrees |
29.0 - 38.0degrees |
| Crown Height |
N/A |
N/A |
| Pavilion Depth |
N/A |
N/A |
| Symmetry |
excellent to very good |
excellent to good |
| Finish |
excellent to very good |
excellent to good |
The
Ideal shape for Princess
cut is @1.0 x 1.0, +/- 10%,
ie:
6mm x 6mm to 6mm x 6.60mm
The
Ideal shape for Emerald and Radiant
cuts are 1.30 x 1, up to 1.40 x 1,
ie:
9mm x 7mm, or, 7mm x 5mm, etc.
Many wonder what the difference is between the Princess cut and the Radiant
cut... well, they are actually the same cut. The difference is in
the shape of the stone. As you can see from the notations above,
Princess cut is "1.0 x 1.0, +/- 10%" so they would be very square in shape.
A Princess cut becomes a Radiant cut when it starts getting more rectangular.
In other words, if the stone measures 7.0mm x 7.7mm (within 10% of being
square) it's still a Princess cut, but if it were 7.0mm x 7.8mm, and anything
beyond that, it should rightfully be called a Radiant cut. A well
proportioned Radiant cut or Emerald cut should be between 1.0 x 1.3, up
to 1.0 x 1.4 (example: 7.0mm x 9.1, up to 7.0mm x 9.8mm). Typically the
Princess cut also has square corners, rather than the cut corners normally
seen on the Radiant and the Emerald cut.
Proportions for
Marquise, Oval, Pear & Hearts
| Components |
Ideal
Proportions |
Near
Ideal Proportions |
| Total Depth |
57.0 - 65.0% |
53.0 - 69.0% |
| Table Diameter |
52.0 - 64.0% |
51.0 - 66.5% |
| Girdle Thickness |
thin to sl.thick |
thin to thick |
| Culet Size |
N/A |
N/A |
| Crown Angles |
33.0 - 34.0 degrees |
31.0 - 36.0 degrees |
| Crown Height |
N/A |
N/A |
| Pavilion Depth |
N/A |
N/A |
| Symmetry |
excellent to very good |
excellent to good |
| Finish |
excellent to very good |
excellent to good |
The
overall shape considered as "Ideal" for Marquise
diamonds is 2 to 1,
i.e:
5mm wide and 10mm long
The
Ideal shape for Oval
cut is 1.30 x 1, up to 1.40 x 1,
i.e:
9mm x 7mm, 7mm x 5mm, etc.
The
Ideal shape for Pear
shape cut is 1.30 x 1, up to 1.40 x 1,
i.e:
9mm x 7mm, 7mm x5mm, etc.
The
"Ideal" shape for a Heart
shape cut is 1 to 1,
i.e:
6mm x 6mm
DIAMOND
- April Birthstone
|
