Carat is often confused with size even though it is actually a measure of weight. One carat is equivalent to 200 milligrams. One carat can also be divided into 100 “points.” A .75 carat diamond is the same as a 75-points or 3/4 carat diamond.
The word "carat" derives from ancient times when gems were measured using the weight of a carob seed.
Generally, the larger the carat, the more rare and valuable the diamond. Two diamonds of the same weight, however, can have very unequal values, depending on their clarity, colour and cut.
A good cut and mount can make a diamond appear larger than its actual carat weight.
The 4Cs : Colour
Refers to the degree to which a diamond is colourless.
Diamond colours are graded from D, continuing through the alphabet to Z. Truly colourless diamonds (graded D) are treasured for their rarity. While still beautiful, lower graded diamonds are less rare.
Choice of colour comes down to personal taste. White colours (D-J) look beautiful set in white gold or platinum; warmer colours (K-Z) are stunning set in yellow gold.
Colour
Description
D
Pure White - the most prized colour
E
Exceptional white - colourless group
F
Excellent white - colourless group
G
Good white - colourless group
H
White - colourless group
I
J
Slightly tinted white/ commercial white
K
Tinted white/ needs yellow setting to look its best
L
Tinted white/ needs yellow setting to look its best
M
Slightly yellowish/Tinted colour-champagne
N
Slightly yellowish/Tinted colour-champagne
O-R
Yellowish/Tinted colour
S-Z
Yellow/Tinted colour
The 4Cs : Clarity
Refers to the presence of inclusions in a diamond.
Most diamonds contain inclusions - natural identifying characteristics such as minerals or fractures. These are known as nature's "birthmarks" or "fingerprints" and may look like tiny crystals, clouds or feathers. The fewer the inclusions, the greater the clarity and the more valuable the diamond.
Inclusions are usually invisible to the naked eye. However, their number, size and location can affect the flow of light through a diamond, causing some of the sparkle to be lost.
Diamonds with inclusions that are visible to the naked eye are graded I1 - I3. Those with small inclusions are graded SI1 - SI2, those with very small inclusions are graded VS1 - VS2 and diamonds with very very small inclusions are graded VVS1 - VVS2. Those rare diamonds with no inclusions are called flawless (FL) or internally flawless (IF).
Some inclusions can be hidden by a setting and have little effect on the diamond's beauty.
The 4Cs : Cut
Refers to the angles and proportions of a diamond.
The cut indicates the physical shape of the diamond and refers to the angles and proportions a skilled craftsman creates in the stone, releasing its fire and sparkle. It is the only one of the 4Cs not determined by nature.
It is the cut that enables the diamond to make good use of light, allowing light to be dispersed and reflected from one facet to another. A well proportioned cut allows the greatest amount of fire and sparkle to be reflected.
If a diamond is cut too deep or too shallow, light escapes through the side or the bottom and the display will be less brilliant. A well cut diamond is more valuable than a poorly cut stone of the same weight, clarity and colour.
Cut also refers to shape - round, square, pear, or heart for example. Since a round diamond is symmetrical and capable of reflecting nearly all the light that enters, it is the most brilliant of all diamond shapes.
The 5th C: Confidence
It's important to find a jeweller you trust and feel comfortable with, one who will take the time to explain to you the characteristics of a diamond.
