When determining the value of a diamond there are 4 things to consider: clarity, cut, color, and carat weight. However, only two of these things affect its “quality.” These are: clarity and cut. Color is merely a measure of how the gem formed, with some colorization of minerals resulting in a rarer form of diamond. Carat weight, of course, is just a measure of the stone’s weight.
HOW CUT AFFECTS QUALITY
The cut of a diamond matters because it affects the way light enters and exits the stone, which results in different qualities of refraction. When cut properly, light enters and refracts back out in a way that is stunning and beautiful. When cut poorly, light refracts outward in a less stellar way:
- When a diamond cut is too shallow, the entering light hits the pavilion facet at a lower angle, of course, and then refracts and escapes through the bottom of the stone.
- When a diamond cut is too deep, the entering light hits the pavilion first at too sharp an angle to refract enough light to the second pavilion. However, when the light does hit the second pavilion, it does so at too low an angle to refract upwards and, again, escapes through the bottom of the stone
- When a diamond is cut properly, though, the entering light hits the first pavilion facet at the appropriate angle and most of it is refracted towards the second pavilion and then upwards again to exit, mostly, through the crown, finally refracting again (in a good way) through the crown facet.
HOW CLARITY AFFECTS QUALITY
The “clarity” of a diamond is determined by how many (or few) imperfections the stone has. Clarity is graded on a scale:
- FL—or Flawless—diamonds have no inclusions or blemishes
- IF—or Internally Flawless—diamonds may have some blemishes but no inclusions
- VVS1/VVS2—or Very Very Slightly Included—diamonds have inclusions that can be found under magnification
- VS1/VS2—or Very Slightly Included—diamonds have inclusions more visible to the naked eye
- SI1/SI2—or Slightly Included—diamonds are the lowest grade to have inclusions not visible to the naked eye
- I1/I2/I3—Included–diamonds have flaws definitely visible to the naked eye
WHAT ARE INCLUSIONS?
An “inclusion” is, basically, some random characteristic of a diamond that occurs within the stone. Generally considered “flaws” they are not always a “bad” thing as they make each stone unique.
There are many types of inclusions:
- Crystal/mineral—crystals or minerals embedded within the stone
- Pinpoint—extremely light or dark crystals that can appear singularly or within a cluster; larger clusters can make the gem cloudy
- Grain/Growth lines—irregular crystallization that occurs during formation
- Feathers—cracks within the diamond (that look like feathers). Larger feathers can affect durability
- Cleavage—a straight crack, no feathering
- Laser lines—unnatural inclusion caused from laser cutting
- Girdle Fringes/Bearding—hair-like lines caused by cutting