What is a Black Diamond?
The trade name for a black diamond is “carbonado”. Carbonado is not traditionally used in jewelry, rather it is typically used in industrial tools. It is described as the toughest form of a natural diamond, but is also an impure form of a diamond which is comprised of diamond, graphite, and amorphous carbon. Natural Black diamonds are primarily made of graphite inclusions which darken the body of the stone to give it a black appearance. Treated Black diamonds are natural gray diamonds that have been treated using high pressure high temperature treatments to enhance the darker tone. Most jewelry features treated black diamonds because of their strength and durability.
How Is It Graded?
You may be familiar with the 4 C’s of diamonds but wondering, what’s the grading system for a black diamond? Black diamonds are evaluated with the same grading of white diamonds in regards to a black diamond’s cut, and carat weight. However, the color and clarity of a black diamond are graded according to the black diamond specific guidelines:
Color
Black diamonds are categorized under the color grading guidelines that all “colored diamonds” are evaluated within. When it comes to colored diamonds, the grading is somewhat subjective. The way people perceive a color and communicate the color to one another varies, so when grading a colored diamond this is taken into account.
There are a number of elements that can effect the way a colored diamond appears, including light source, the surrounding environment of the diamond, and the person viewing the diamond. To provide an authoritative reference of color, the Gemological Institute of America (GIA) compiled a collection of what is known as “masterstones” that provide a reference point to what the color of the diamond should look like, or come close to looking.
Taking the steps written above and combining that with expert color graders and neutral environments to analyze a stone within has created a process that is easily repeatable with minimal subjectivity to ensure accurate descriptions of a diamond’s color.
Clarity
When looking through most black diamonds, they are opaque, meaning you cannot see through a stone like you can with a white diamond. Furthermore, it is common for a black diamond to be heavily included, meaning the diamond has imperfections within the stone. However, these inclusions are not necessarily visible to the naked eye.
There is no variety in the tone and saturation of a black diamond, therefore they are referred to in the grading system as “Fancy black”. For example, when the GIA provides a grading report for a black diamond, it is called a “Colored Diamond Identification and Origin Report”, in which the diamond is referred to as “Fancy black” and the color is either denoted as natural or treated.