The overwhelming majority of diamonds possess a tint of color, (Only “D” color diamonds are truly colorless). In most, this color is a faint yellow. However, some diamonds, termed Top Light Brown (TLB), exhibit a faint brown instead. Diamond color only becomes noticeable within the “J-Z” color grades, so “TLB” diamonds are only found within this range.
The Gemological Institute of America, (The world’s foremost authority on diamonds), does not differentiate between Top Light Brown diamonds and standard diamonds. This means that, all other factors being equal, a GIA Certified “J” color “TLB” diamond will received the same color grade as a GIA Certified “J” color standard diamond.
When viewed from the top (Mounted), it is almost impossible to differentiate between a Top Light Brown diamond and a regular diamond. In fact, TLB diamonds often appear slightly whiter! Below are two GIA Certified J Color, SI1 clarity diamonds. The Top Light Brown diamond is located on the left.
When viewing these same diamonds from the side, the color difference becomes much more apparent.
While not necessarily less appealing, Top Light Brown diamonds are viewed unfavorably within the industry, and trade at a significant discount to standard diamonds.
Because “TLB” diamonds are difficult to detect when mounted, unethical sellers may mount them in a jewelry piece and sell them, without disclosing their “TLB” quality to the consumer. Avoid this by requesting a written guarantee that your jewelry piece does not contain any Top Light Brown diamonds.
The best way to determine if a diamond is top light brown is to compare it to one that isn’t. Other options include taking it to a trustworthy gemologist. If the diamond is un-mounted, you may be able to tell if it is “TLB” by placing it face down on a white surface and inspecting it from the side for a brownish tint.