Almost all diamonds grow in nature with markings inside and outside. The inside markings are called flaws and the surface markings are called surface blemishes. Some of the typical ones are called:
• Feathers
• Cleavages
• Crystals
• Clouds
• Bruises
• Graining
• Naturals
• Twinning
Diamonds containing very few of these are more rare and expensive, and conversely, diamonds containing more of these are more common and less expensive.
Gemologists study five features of these markings. They are:
• Number of flaws
• Size of flaws
• Types of flaws
• Position of flaws
• How flaws affect the passage of light through the diamond
The most universally accepted clarity grading systems are those developed by the GIA (Gemological Institute of America) and the AGS (American Gem Society). The meaning given to the grades within these systems should be considered the industry standard. Knowing the clarity grade of your diamond is interesting and important to your insurance company, but it doesn’t give you much information about your stone. Here are the questions to ask your jeweler to get to know your diamond inside and out:
• Do any of the markings in your stone affect durability?
• If these flaws cannot be seen with the naked eye, do some of them become visible when the diamond is not clean?
• Are any of the flaws on the edge of the diamond?
• Do any of the flaws open onto any surface of the diamond?
• Are any of the flaws crystals of other minerals that are typically found in diamonds?
• Are the flaws centrally located or dispersed to the perimeter of the stone?
Asking these questions of your jeweler will help you understand the value of your purchase and how that value is affected by the diamond’s internal and external markings. This will also help you pinpoint cost, as there are many diamonds within the same clarity grade, which carry different prices based on their features. It is not the clarity grade you are after; rather, it is the characteristics themselves that should influence your decision to purchase.


