Last updated on March 29, 2023
Many think that clarity enhanced diamonds are a cost-effective way to buy larger-carat stones. While enhancement helps to get rid of annoying inclusions and improve diamond clarity, it is important to understand that such stones have pitfalls that you need to be aware of.
What Are Clarity Enhanced Diamonds?
Clarity enhanced diamonds are natural stones that used to have eye-visible imperfections and have undergone treatment to remove them. In other words, these were diamonds that were in included clarity range (I1, I2, I3) and have had “plastic surgery” to hide or make the inclusions less visible.
In the diamond industry, there are two main techniques of clarity treatments: laser drilling and fracture filling.
It is important to note that jewellers are required by law to fully disclose if the diamond has been clarity enhanced regardless of the improvement type. So do not hesitate to ask if the diamond has been treated because many jewellers are not quick to disclose that info before making the sale.
Laser Drilling
Laser drilling is a technique used to remove inclusions such as black spots or foreign crystals embedded within a diamond’s crystalline structure.
During this process, a thin channel is drilled with a laser beam from the surface to the inclusion of the diamond. Through the channel acidic chemicals (typically hydrofluoric acid (HF) and sulphuric acid (H2So4)) are forced into the opening to dissolve and bleach out the inclusions. After dissolving the inclusion, there is a space left in that place. The resulting hollow inside the diamond would be still considered a type of flaw, but it would not be visible. As for the tunnel drilled in the stone, it is usually extremely thin and practically invisible to the naked eye. It can be seen only with a microscope.
The clarity of diamonds after laser drilling can usually increase by up to one grade, sometimes even more. The downside of laser drilling is that it can weaken the diamond’s structure. That is not a problem if there are just a few holes drilled, but if the stone has a lot of inclusions removed this way, the resulting cavities and channels can make it easier to break.
It is important to understand that laser-drilled diamonds usually originate from low-quality stones that are not desirable and saleable. 99% of enhanced diamonds have poor cut quality because it does not make sense to pay attention to achieving ideal cut standards.
Fracture Filling
Fracture filling is another technique used to improve diamond clarity. As the name suggests, it hides fractures (feathers) in a diamond. Although surface-reaching feathers can be removed through polishing, fracture filling is more favoured as it does not lead to significant carat weight loss.
During this process, a transparent crystalline substance is injected into surface fractures (scratches and cracks) to make them less visible after the filler is solidified. You should realize that a fracture-filled diamond is no longer made of uniform material, and the injected filler reflects light differently, which is why it can change the stone’s sparkle.
It is important to mention that fracture filling is not permanent. The material used to fill the diamond can melt or crack if a jeweller uses heat to repair your jewellery piece. Besides, once a diamond is fracture-filled, it should not be put in an ultrasonic cleaner as it will damage the filling.
Because of the non-permanent nature of fracture-filled diamonds, most companies selling such stones offer lifetime repairs for their products. However, the second filling will never be as good as the first one because once a diamond is filled with resin it is impossible to reverse the process.
Should You Buy Clarity Enhanced Diamonds?
Although clarity enhanced diamonds may seem appealing to many customers due to their low price, there is a reason for their being affordable. The main problem with such stones is that they were undesirable stones in low clarity grades presented as innovation and compared to properly graded diamonds.
The truth is that unethical jewellers try to provide you with the false impression that clarity enhanced diamonds are worth more than they are. For example, a natural SI2 clarity diamond can never be compared with an enhanced SI2 diamond that used to have I1 clarity before the treatment. An enhanced diamond can never be a better deal, even if it costs less than an untreated diamond with the same parameters.
Moreover, the GIA (Gemological Institute of America) does not issue grading reports for stones that have undergone non-permanent or unstable treatment processes such as fracture filling. They will issue reports for laser-drilled diamonds because this process is permanent but will disclose the presence of the treatment in the report.
Featured image: Edgar Soto / Unsplash
