THE FOUR CS OF DIAMOND VALUE
. CLARITY
. COLOUR
. CUT
. CARAT WEIGHT
The most important part of purchasing a diamond is your trust in
your jeweller. The jeweller's reputation, how long they have been in
business, there credentials, (Gemmologist, diamonds graduate etc.),
trade affiliations (member of the Canadian Jewellers Association),
what type of service and after care for your diamond ring, will your
receive, and your impression, perception and feeling when you first
meet with the person you will be possibly making the most important
purchase of your life with.
The second most important part of your purchase is your budget.
Always keep it in mind to help you determine which of the four c's
is most important to you the buyer, because most times people can
not afford the biggest and the best in all 4 of the c's. A good
jeweller can show you many different stones with many different
combinations of the 4 c's to help determine which diamond is best
for you.
I hope the following descriptions will assist you with your
purchase.
Clarity refers to a stones relative position on a flawless-to
imperfect scale. Clarity characteristics are classified as
inclusions (internal) or blemishes (external). The size number,
position, nature, and colour of the characteristics determine the
clarity grade. Very few diamonds are flawless, that is, show no
inclusions or blemishes when examined by a skilled grader under 10 x
magnification. If other factors are equal, flawless stone are most
valuable.
CLARITY GRADING SYSTEM
F.L. FLAWLESS GRADE
FLAWLESS DIAMONDS SHOW NO BLEMISHES OR INCLUSIONS WHEN EXAMINED BY A
SKILLED
AND EXPERIENCED GRADER UNDER 10 X MAGNIFICATION.
I.F. INTERNALLY FLAWLESS
INTERNALLY FLAWLESS DIAMONDS SHOW NO INCLUSIONS AND ONLY
INSIGNIFICANT BLEMISHES UNDER 10 X MAGNIFICATIONS. IF FROM FI STONES
ARE CHARACTERISTICS
THAT CAN BE REMOVED BY MINOR REPOLISHING.
V.V.S. VERY VERY SLIGHTLY INCLUDED
VVS DIAMONDS CONTAIN MINUTE INCLUSIONS THAT ARE DIFFICULT FOR EVEN A
SKILLED GRADER TO LOCATE UNDER 10 X MAGNIFICATION. IN VVS 1 THEY ARE
EXTREMELY DIFFICULT TO SEE, VISIBLE ONLY FROM THE PAVILLION, OR
SMALL AND SHALLOW ENOUGH TO BE REMOVED BY MINOR REPOLISHING. IN VVS
THEY ARE VERY DIFFICULT TO SEE.
V.S VERY SMALL INCLUSIONS
VS STONES CONTAIN MINOR INCLUSIONS RANGING FROM DIFFICULT (VS1) TO
SOMEWHAT EASY (VS2) FOR A TRAINED GRADER TO SEE UNDER 10 X
MAGNIFICATION. SMALL
INCLUDED CRYSTALS, SMALL FEATHERS, AND DISTINCT CLOUDS ARE TYPICAL.
S.I. SMALL INCLUSIONS
SI DIAMONDS CONTAIN NOTICABLE INCLUSIONS WHICH ARE EASY (SI1) OR
VERY EASY
(SI2) TO SEE UNDER 10 X MAGNIFICATION
I. INCLUDED
I GRADE DIAMONDS CONTAIN INCLUSIONS WHICH ARE OBVIOUS TO A TRAINED
GRADER UNDER 10 X MAGNIFICATION, CAN OFTEN BE EASILY SEEN FACE UP
WITH THE UNAIDED EYE, SERIOUSLY AFFECT THE STONES POTENTIAL
DURABILITY, OR ARE SO NUMEROUS THEY AFFECT TRANSPARENCY AND
BRILLIANCE.
Colour grading in the normal range involves deciding how close a
stones body colour approaches colourless. Most diamonds have at
least a trace of yellow or brown body colour. With the exception of
some natural fancy colours, such as pink, purple or red the
colourless grade is the most valuable.
COLOUR GRADING
COLOURLESS D EXCEPTIONAL WHITE+
E EXCEPTIONAL WHITE
F RARE WHITE
NEAR COLOURLESS G WHITE
H WHITE
I SLIGHTLY TINTED
J SLIGHTLY TINTED
K TINTED WHITE
SLIGHTLY COLOURLESS L TINTED WHITE
M TINTED
N TINTED
VERY LIGHT YELLOW O TINTED
P TINTED
Q TINTED
LIGHT YELLOW R TINTED
S TINTED
T TINTED
YELLOW U TINTED
V TINTED
W TINTED
X TINTED
Y TINTED
Z TINTED
Carat weigh is the metric carat, which equals 0.200 gram, is the
standard unit of weight for diamonds and most other gems. If other
factors are equal, the more a stone weighs, the more valuable it
will be.
Do not confuse carat with karat. Carat refers to stone weight, while
karat refers to fineness of gold.
Cut. The proportion and finish of a polished diamond are it cut, or
make.
Cut can also mean shape, as in emerald cut or princess cut.
Proportions are the size and angle relationships between the facets
and different parts of the stone. Finish includes polish and
symmetry, (details of facet shape and placement), cut affects both
the weight yield from rough and the optical efficiency of the
polished stone; the more success the cutter is in balancing the
considerations, the more valuable the stone will be.
There has been much debate and research into this subject of cut. It
is the only part of the four c's that does not have a standardized
system.
Proportion: Each gemmological lab has its own word grading systems.
IDEAL, EXCELLENT, VERY GOOD, GOOD, MEDIUM, FAIR, are some word terms
used. These word terms are based solely on the proportion part of
cut grading. The illustration below shows the range of measurements
included in the ideal terminology. Some labs only use these terms in
regards to polish and symmetry, and will give you the measurements
of the stone along with the depth percentage, table percentage, and
some labs will give you the crown angle and height also.
I repeat each lab has its own standard, but generally follow the
same guidelines.
Polish: is just what is sounds like. Laboratories will look for:
Abrasions
Bearded girdles
Nicks
Pits
Polish lines
Polish marks
Rough girdles
Scratches
Abraded culet
Symmetry: again these word terms, IDEAL, EXCELLENT, VERY GOOD, GOOD,
MEDIUM, FAIR are used to describe the symmetry. To determine if the
diamond is symmetrical a laboratory will look for things like
Table or culet off centre
Girdle outline is out of round
Table or girdle not parallel
Girdle wavy
Facets fail to point properly
Misaligned crown and pavilion facets
Misshapen crown or pavilion facets
Misshaped facets
Table and girdle not parallel
Naturals
Extra facets
