Diamond stones may be considered by some to be a mineral miracle. These gorgeous, sparkly gemstones are the direct result of carbon deposits that were formed millions or billions of years ago. Deep within the earth, intense pressure and heat combine to transform these carbon deposits into a diamond rock. The rocks are then carried to the earth’s surface through lava flows and are eventually mined and made into exquisite diamond jewelry. The diamond has truly gone through a timeless journey from deep within the earth to the jewelry retailer. As the diamond is being formed, inclusions, or defects, within the diamonds structure may occur. In fact, it is extremely rare to find a completely flawless diamond stone; however those that do exist are exceptionally valuable.
The Clarity Grading Scale
Each diamond is classified according to their clarity, or the amount of inclusions the diamond contains. Inclusions can make a diamond appear chalky and affect the stone’s ability to reflect and disperse light. Fewer inclusions will result in a more brilliant stone. The diamond is carefully evaluated to determine the size, number, nature, relief, and position of each inclusion or blemish that exists within the stone. They are then graded on a clarity scale. The Gemological Institute of America uses six categories and 11 specific grades to classify the stone’s clarity. The American Gem Society laboratories also include a numerical grade of clarity. These categories and numerical grades include:
- Flawless (0): No blemishes or inclusions can be seen under 10X magnification.
- Internally Flawless (0*): No internal inclusions can be found under 10X magnification.
- Very, Very Slightly Included (1 or 2): Inclusions do exist; however, they are so small that only a skilled grader can identify them under 10X magnification.
- Very Slightly Included (3 or 4): Inclusions can be seen under 10X magnification but they are extremely minor.
- Slightly Included (5 or 6): Inclusions are readily identifiable under 10X magnification.
- Included (7, 8, 9, or 10): Inclusions are obvious and may affect the brilliance and transparency of the diamond.
Determining Clarity
There are certain factors that are used to evaluate diamond inclusions. The size of each inclusion is important, as it will ultimately determine how the stone reflects light. It will also affect the total transparency of the stone. The nature of the inclusion is also considered by identifying its depth within the stone. Surface blemishes may include scratches or marks on the exterior of the stone. Generally speaking, the more blemishes and inclusions within the diamond, the lower its clarity grade will be.
The location of the inclusions and blemishes will also affect the clarity grade. Inclusions that are close to the center and radiate toward the top of the diamond, or pavilion, may affect the durability of the stone. Inclusions and blemishes that exist toward the top of the diamond may hinder the stone’s ability to reflect light. When the stone is cut, it is shaped using facets that are strategically placed in an attempt to maximize light reflection. Blemishes and inclusions may get in the way of these facets and affect the stone’s ability to reflect light.
When going in to purchase a diamond, it is extremely helpful to have a general idea of the clarity scale and how it works. This gives the diamond buyer the ability to purchase the best diamond possible.
