What are the 4 C’s of diamonds?
A diamond’s quality is determined by the 4C’s. The grades a diamond carries in these four areas give a clear idea of the diamond’s quality, and by extension the right price you should be willing to pay.
- Cut: Quality of the angles, proportions, facets, and finishing details.
- Color: How colorless the diamond is
- Clarity: How clean the diamond is of inclusions and blemishes.
- Carat: The weight of the diamond.
CUT
Diamonds are renowned for their ability to transmit light and sparkle so intensely. We often think of a diamond’s cut as shape (round, heart, oval, marquise, pear), but a diamond’s cut grade is really about how well a diamond’s facets interact with light. Precise artistry and workmanship are required to fashion a stone so its proportions, symmetry and polish deliver the magnificent return of light.
TYPES OF CUT
Ideal cut
In a well cut diamond, the light strikes each pavilion facet at an angle which allows most of the light to reflect back to the crown (top). As it passes through the crown facets at a low angle, the light refracts upon exit. In this case, refraction is a good thing, as the bent light travels to the observer’s eye and is perceived as a lively fire.
Shallow cut
If the diamond cut is too shallow, entering light strikes the pavilion facet at a low angle and passes through the facet (refracts), escaping through the bottom of the diamond.
Deep cut
If the diamond cut is too deep, entering light strikes the first pavilionfacet at an angle sharp enough to reflect to the second pavilion. But the light strikes the second pavilion at too low an angle, causing the light to refract (pass through the facet), escaping through the bottom of the diamond.
CUT GRADE
EXCELLENT
An excellent cut diamond has a maximum amount of scintillation, brilliance and fire. Light enters the diamond and refracts back out with very little light lost. This exceptional grade represents roughly the top three-percent of diamonds.
VERY GOOD
A diamond with a very good cut grade will reflect most of the light and will appear somewhat similar to an ideal cut diamond. This diamond will have superior sparkle, brilliance and fire.
GOOD
Reflecting most of the light entering the diamond, this diamond cut has above average beauty. Diamonds with this grade won’t have as much brilliance and fire as higher cuts.
FAIR
Diamonds graded Fair don’t have the optimum brilliance and fire, as they allow a significant amount of the entering light to exit on the bottom or side of the diamond instead of through the top. These are still quality, but not nearly as well performing as a finer cut.
POOR
Diamonds with a poor cut may appear dull because the majority of the light is lost through the bottom or sides of the diamond. With a noticeable decrease in sparkle, even an untrained eye can see a sharp difference between this and higher cuts.
COLOR
Diamond Color is graded in terms of how white or colorless a diamond is. The GIA grades diamonds from D to Z, with D being the most colorless, and Z containing noticeable brown or yellow tint.
Note – Diamond color and Fancy colors are two different subjects.
D E F
While there are differences in color between D, E, and F diamonds, they can be detected only by a gemologist in side by side comparisons, and rarely by the untrained eye. D-F diamonds should only be set in white gold / platinum. Yellow gold reflects color, negating the diamond’s colorless effect.
G H I J
While containing traces of color, G-J diamonds are suitable for a platinum or white gold setting, which would normally betray any hint of color in a diamond. Because I-J diamonds are more common than the higher grades, they tend to be a great value. An I-J diamond may retail for half the price of a D diamond. Within the G-J range, price tends to increase 10-20% between each diamond grade.
K L M
Beginning with K diamonds, color (usually a yellow tint) is more easily detected by the naked eye. Set in yellow gold, these warm colored diamonds appeal to some, and are an exceptional value. Others will feel they have too much color. Due to its perceptible color tint, a K diamond is often half the price of a G diamond.
N – R
Diamonds in the N-R color range have an easily seen yellow or brown tint, but are much less expensive than higher grades.
S – Z
These diamonds have too much color for a white diamond.
CLARITY
A Diamond’s Clarity grade evaluates how clean a diamond is from both inclusions and blemishes. Clarity is graded by the GIA on the following diamond clarity chart:
- FL (Flawless)
- IF (Internally Flawless)
- VVS1 (Very, Very Slightly Included 1)
- VVS2 (Very, Very Slightly Included 2)
- VS1 (Very Slightly Included 1)
- VS2 (Very Slightly Included 2)
- SI1 (Slightly Included 1)
- SI2 (Slightly Included 2)
- I1 (Inclusion 1)
- I2 (Inclusion 2)
FL (Flawless)
No inclusions and no blemishes visible under 10x magnification
Very, Very Slightly Included (VVS1 and VVS2)
Inclusions so slight they are difficult for a skilled grader to see under 10x magnification
Very Slightly Included (VS1 and VS2)
Inclusions are observed with effort under 10x magnification, but can be characterized as minor
Slightly Included (SI1 and SI2)
Inclusions are noticeable under 10x magnification
Included (I1, I2and I3)
Inclusions are obvious under 10x magnification which may affect transparency and brilliance
CARAT
Often when people hear the term “Carat Weight,” they think it refers to the size of the diamond. In actuality, Carat refers to the weight of the diamond, not how large the stone is. Depending on the Diamond Shape and how it is cut, two 1 Carat Diamonds might be quite different in size.
1 Carat = 200 Milligrams
5 Carat = 1 Grams
Diamond Carat Size Comparison
- Approximate size The diamond images shown are a very close approximation of the actual size of a 1 carat excellent cut for each shape. Visually, the longer shapes (oval, marquise, pear, emerald) tend to appear larger to the eye than the round and square shapes.
- Measurements (Length x Width) The measurements correspond to the shape shown above, and are typical for excellent cut diamonds of 1 carat weight.
- Crown Area – The total surface area (mm2) The area gives the true size of the diamond face up (as it would appear when set in a ring). For example, while the oval diamond image appears larger than the round image, the actual surface area is the same for the two shapes, meaning the difference in size is one of perception, not reality. In contrast, the oval not only appears larger than the princess cut, it actually has a larger surface area (approximately 10% larger in this example), meaning the difference is not simply an illusion created by the elongated shape.