The clarity of a diamond 4 C's of diamonds Glossary of terms Jewelry colour of diamond ~ 1Earth Antiques and Appraisals Magazine

GIA Scales GIA Diamond D-Z Color Scale

DIAMOND CLARITY

No two diamonds are alike. A diamond's most distinguishing characteristics are its inclusions, marks that are often invisible to the naked eye. However, under a jeweller's magnifying loupe or microscope they can look like crystals, tiny rivers, or clouds. A diamond's clarity is determined by the presence or absence of inclusions--fewer inclusions mean better clarity--and how visible they are. The greater a diamond's clarity, the greater its brilliance and value. A diamond categorized as internally flawless will have no inclusions, but this is extremely rare.

There are four grades to diamond inclusions:

Included (I)
Slightly Included (SI)
Very Slightly Included (VSI)
Very Very Slightly Included (VVSI)

Diamonds with very, very small inclusions are graded as VVS1 or VVS2. Those with larger inclusions are considered lower-grade. Diamonds with inclusions that are visible with the naked eye are graded I1 to I2.

If the inclusion(s) can be seen without the microscope or hand loupe it can be assumed that the grade is SI₂ or lower. Of course, if no inclusions or blemishes are visible with 10x magnification then the diamond is flawless.

On a certificate or well done appraisal these internal and external characteristics are recorded on a diagram called a plot. All inclusions are plotted in red, blemishes in green, and extra facets and prongs in black. The following are lists of some internal and external characteristics.

EXTERNAL CHARACTERISTICS

natural - unpolished surface, the original skin of the diamond rough
pit - small indentation on a facet surface
cavity - opening on surface
nick - minor surface chip
grain/twinning line - irregularity in atomic grain, the crystal growth
scratch - small groove (can be from normal wear)
abraided facet junction (can be from normal wear)
out of round - diamond circumference not symmetrically round

INTERNAL CHARACTERISTICS

cleavage or feather - occurs along atomic grain
fracture - irregular shaped break
included crystal
carbon spot - included crystal (dark)
pinpoint - small included crystal (appears white)
cloud (group of pinpoints)
internal grain line
laser drill hole
bearded or feathered girdle - minute to small hairline fractures extended from the girdle into the stone

The clarity not only dramatically affects the price, but can be a good indication of the diamond's vulnerability. Heavily included diamonds can be dangerous to wear because the type and number of inclusions present could make it prone to breaking. Again, this is why accurate information presented in a precise, understandable manner is paramount in your quest to purchase the diamond that meets your needs as a good value.

TREATMENTS

Take another look at the included and slightly included stones below. The features circled are inside the stones.

If someone could only fill up those inclusions with something clear, the diamonds might look much better, right? The grading would probably be higher too. Even a jeweler might have a difficult time detecting the difference. This is true, and it's one of the problems. While the treated stone is prettier than it originally was, it still has most of the vulnerablity of the original inclusion.

However, there is an additional problem that can be caused by even the smallest fracture filling. If you or anyone else ever needs to have the mounting worked on, requiring the use of a torch, and the jeweler is not informed that the stone is fracture filled there is an enormous likelihood that the stone will weaken more, original inclusions may become apparent or even increase in size and the stone may shatter or break. For this reason many jewelers will refuse to work on fracture filled stones.

The reason this may happen is that the diamond does not respond to heat from the torch the same way as the filling. As the filling heats it expands and puts pressure on the weakest part of that diamond.

Another reason not to purchase a fracture filled diamond is more personal. In many people's opinion, the fracture filled diamond is second rate. Diamonds are usually worn because they make the wearer proud of their natural beauty and rarity. It feels good to have something fine.