Treated Diamonds: Clarity Enhancement and Fracture Filled Diamonds 

Specialists have long tried to enhance and restore defected diamonds. They have done this by filling the fractures or cracks, a process that is known as clarity enhancement. This was developed in 1982 by Zvi Yehuda, a diamond cutter from Israel. Clarity enhancement results in the improvement of the diamond's brilliance, however, it can only be used on a diamond that has minute cracks. It will improve the clarity grade by one grade, and it won't have an effect on the stone's additional elements, such as colour or weight. 

A fractured diamond that has been filled can be spotted with relative ease. It may not be visible to the naked eye. Nevertheless, you simply need to get a microscope and shake the stone. You will know that it has been tampered with if you see the colour span from a purple shade to a yellow colour. 

Advantages

Boost the clarity grade - Clarity enhancement can improve the clarity grading of the diamond by one grade.

Low cost - This gives people the ability to purchase a diamond that is bigger in size and cleaner. They may not have been able to afford such a diamond if it had not needed to go through the clarity enhancement process. 

Disadvantages

Is it really low cost? - There is an argument that you will not save any money by going for this option. Experts argue that while you may get more value for your money, you will still need to spend the same amount.

Buying process is complicated - Clarity enhancement makes it difficult for the customer to know if they are getting a good deal and how much they should spend. 

Appearance diminishes - A lot of experts note that over time the appearance of the stone will diminish and thus you are not really benefitting from a higher grade of diamond.

Not all stones are suitable - There is actually a small proportion of stones that are suitable for this procedure, as most tend to be either too small or not of a high enough quality.