A treated diamond refers to a diamond that has undergone artificial enhancement to improve one or more of its natural characteristics, typically either its colour or clarity. These treatments can significantly alter the appearance of the diamond from its original state, and they may influence its value and marketability. As a result, any treatment a diamond has undergone must be fully disclosed to ensure transparency in the diamond’s history and characteristics.
Diamonds that are treated are usually more affordable than untreated diamonds with similar characteristics because the treatments aim to improve attributes such as colour intensity or the visibility of inclusions. However, treated diamonds are often valued less than their natural, untreated counterparts due to the fact that they do not retain the same rarity or intrinsic value.
Types of Diamond Treatments
Laser Drilling:
Laser drilling is a process used to reduce the visibility of inclusions, especially those near the surface of the diamond. A laser is used to create a small hole into the diamond, which is then filled with a material such as glass or resin to make the inclusion less noticeable.
While laser drilling can improve the clarity of a diamond, it leaves behind tiny, microscopic marks that are visible under magnification. These marks should be disclosed on a grading report.
High-Temperature, High-Pressure (HTHP) Treatment:
The HTHP method is used primarily to improve the colour of diamonds, especially those with a lower colour grade (yellow or brown diamonds). This treatment involves subjecting the diamond to high temperatures and pressures, simulating the conditions under which diamonds form in the earth.
HTHP treatment can also be used to enhance the natural blue or green colour of diamonds. However, it can cause some diamonds to change colour in ways that are not predictable, and the effects of the treatment can sometimes fade over time.
Laser Ablation:
Laser ablation is a process used to remove or reduce the appearance of inclusions and blemishes in a diamond. In this treatment, lasers are used to burn away the inclusions, leaving behind a clearer stone.
This process is more precise than laser drilling and can be used to remove darker inclusions, making the diamond appear cleaner. However, like laser drilling, it leaves small marks that can be detected under magnification.
Clarity Enhancement:
Clarity enhancement includes methods like laser drilling and fracture filling (where fractures in the diamond are filled with a special resin to make them less visible). These treatments aim to improve the diamond’s clarity grade by reducing the visibility of inclusions or fractures.
Clarity enhancements can have a lasting effect on the diamond’s appearance, but the treatments may also affect the diamond’s durability over time, especially in the case of fracture filling.
Fracture Filling:
Fracture filling is a treatment designed to improve the clarity of diamonds with visible cracks or fractures. A special filling material is injected into the diamond’s surface cracks, which makes the fractures less noticeable.
The filling material used in this process can sometimes wear away or discolor over time, especially if exposed to heat or certain chemicals. This makes fracture-filled diamonds potentially less durable in the long term.
Ion Implantation:
Ion implantation is a technique used to modify a diamond’s colour by implanting small amounts of specific elements, such as nitrogen or boron, into the diamond’s surface. This can change the diamond’s hue to a desired shade, often enhancing or altering the diamond’s overall colour.
While this method can create vibrant colours, the resulting diamond may not be as durable as untreated diamonds because the process only affects the surface layer, leaving the rest of the diamond in its natural state.
Coating:
Some diamonds are treated with a coating to improve their appearance. These coatings can enhance the colour, giving the diamond a more intense hue, or improve the clarity by hiding inclusions. Common coatings include diamond-like carbon (DLC) or enhancement coatings.
Coatings are often temporary and can wear off over time, especially if the diamond is exposed to harsh conditions such as abrasion, heat, or chemicals.
Colour Enhancement:
This treatment is primarily used on diamonds that are near the lower end of the colour scale, often brown or yellow diamonds. Using various techniques, including the HTHP method, lasers, or irradiation, the natural colour of the diamond can be enhanced to give it a more vibrant and desirable hue.
Colour-enhanced diamonds are often referred to as “fancy colour diamonds” if they fall into specific ranges of colour intensity and saturation, such as blue, green, or pink. However, the enhancement process must be disclosed, as it can impact the overall value and authenticity of the diamond.
Irradiation:
Irradiation involves exposing diamonds to radiation to alter their colour, often producing intense blues, greens, or other rare colours. The treatment can also be combined with the HTHP process to deepen the colour of diamonds.
Irradiation treatments can result in a permanent change to the diamond’s colour, but these diamonds are still considered treated diamonds and should be evaluated for their overall condition and authenticity.
Disclosure of Treated Diamonds
Because treated diamonds have undergone artificial enhancement, their treatments must be disclosed when they are bought, sold, or traded. Failure to disclose a diamond’s treatment status can be considered fraudulent and may lead to legal consequences. It is crucial for consumers and dealers to understand that while treated diamonds may offer a more affordable option, they typically hold a lower value than natural, untreated diamonds due to the fact that their characteristics have been artificially altered.
Market Considerations and Value
The value of a treated diamond is typically lower than that of a natural, untreated diamond with similar appearance and specifications. This is because treated diamonds are considered less rare and may not have the same long-term durability. Additionally, the resale value of treated diamonds is often lower due to the artificial nature of the enhancements.
Fancy Colour Treated Diamonds are an exception in some cases, where treated diamonds with vibrant, rare colours such as blue or green may still command a premium, especially if the colour enhancement is carefully controlled and results in a highly sought-after hue.
Treated diamonds have been artificially altered to improve their colour or clarity, making them more affordable and attractive to some buyers. However, the treatments can affect their long-term durability and value, so it is crucial for both buyers and sellers to fully disclose any treatments performed on a diamond. Transparency in the market helps to maintain trust and allows customers to make informed decisions when purchasing diamonds.