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Diamond Grading

The Four Cs of Faceted Diamonds
The four Cs provide a standard for evaluating Diamonds.

The first step in helping our customers choose diamonds is to clearly convey the meaning
and importance of the Four Cs; color, cut, clarity, carat weight.
Many customers are often not well informed. Here we offer this information to
help you understand the importance of the Four Cs.



 
 
 


Color:
Diamonds can cover the entire spectrum of colors. The majority range from a perceptible yellow or brownish tint up to the very rare diamonds described as colorless. Colorless diamonds are the most desirable since they allow the most refraction of light (sparkle). Off white diamonds absorb light, inhibiting brilliance. You can best observe diamond color by placing the stone table side up on a flat white surface or grading trough, and examining it from different angles. Next, place it table-side down with the culet facing you, and examine it through the pavilion facets.
Cut:
Cut has the greatest influence on the diamonds fire and brilliance. A round, brilliant-cut diamond has 28 facets. When well proportioned, this shape best shows the stones brilliance because it allows the most light to be refracted back to the eye of the observer. Stones that appear lifeless or stones that appear dark in the center are poorly cut. When the angle relationship between the crown and pavilion facets is correct, rays of light entering the diamond strike the rear facets at an angle greater than the critical angle. (24.5 degrees for diamond), and reflect back to the eye of the observer. If the stone is cut too deeply the light strikes the rear facets at an angle less than the critical angle and the light is lost through the sides of the diamond. If the diamond is cut too shallow, the light passes through the diamond without being reflected back. (no sparkle).
Clarity:
Most diamonds contain minute traces of non-crystallized carbon in internal stress factors. Called inclusions, most of these are not apparent to the naked eye but can be seen under magnification. Perfect clarity means that no inclusions are discernible when the diamond is examined under a 10x magnification lens. Inclusions greatly effect the beauty and value of a diamond because they absorb the light rather than allowing it to be reflected back through the front side of the stone. How much they reduce the value of a diamond depends on their size, number and position throughout the stone. An inclusion in the center of the diamond beneath the table is more visible than one near the edge. The inclusion may also be mirrored many times by adjoining facets.
Carat Weight:
The term "CARAT" comes from the ancient practice of weighing diamonds against the seeds of a carob tree. The system was eventually standardized, and one carat was fixed at 0.2 grams. One carat is divided into 100 points, so a quarter-carat diamond is 25 points or 0.25 carat. Although carat is a unite of weight, not size, the carat weight of a diamond has come to refer to particular sizes. If properly cut, diamonds of the same weight should be about the same size. These sizes do not apply to other gems, however, because their specific gravity's differ from a diamond.

One must be very careful when buying diamonds, many diamond brokers have
no formal gemological training or the proper gem testing equipment to "Accurately"
evaluate diamonds. The job of diamond evaluation should only be performed
by a certified Graduate Gemologist who has many years experience in this field!

G.I.A COLOR SCALE



D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z

Colorless
Near Colorless
Faint Yellow
Very Light Yellow
Light Yellow
Fancy Yellow

G.I.A CLARITY SCALE



FL:
Flawless
No blemishes or inclusions when viewed under 10X magnification.
IF:
Internally Flawless
No inclusions and only insignificant surface blemishes under 10X magnification.
VVS1 and VVS2:
Very very slight inclusions
Minute inclusions that are difficult to see under 10X magnification.
VS1 and VS2:
Very slight inclusions
Minor inclusions ranging form difficult to somewhat easy to see under 10X magnification.
SI1 and SI2:
Slight inclusions
Noticeable inclusions that are easy to see under 10X magnification, although appear clean to the naked eye.
I1, I2 and I3:
Imperfect
Obvious inclusions that are usually visible to the naked eye while stone is viewed face up.