Diamonds are treated for various reasons such as to improve its clarity or change its color. Nowadays, it's important to know if your diamond is treated or not because sometimes it's hard to know after a first-glance. Also, if you do decide to buy a treated diamond, make sure that your jeweler informs you about the treatment your diamond received and how to take care of it to ensure that your diamond can look its best for years to come.
There are several diamond treatments:
Fracture Filling- This type of treatment is also known as glass infilling or clarity enhancement. With this process, cracks in the diamond are filled with a glass-like film which makes the cracks appear almost invisible. This process was developed by Zvi Yehuda, an Israeli inventor, in 1982. The filling substance used in this particular treatment can be affected by direct heat, the sun's ultraviolet radiation and cumulative exposure to cleaning procedures which is why fracture-filled diamonds are not always durable. Fracture-filled diamonds are also referred to as clarity enhanced diamonds. Although consumers might think that a clarity enhanced diamond is better than an untreated diamond, it's not. In fact, clarity enhanced diamonds are less valuable than untreated diamonds.
There are three ways to detect a fracture-filled diamond:
- Color Flashes- You can rotate or rock the diamond to see if there are flashes of color in the filled areas.
- Trapped Bubbles- You can look in the diamond to see if there are any trapped bubbles in the filling.
- Cloudy Filled Areas- If you notice "white clouds" within the stone, then your diamond is fracture-filled. These white clouds may appear as clusters of tiny bubbles.
It's better to examine fracture-filled diamonds with a binocular microscope than a loupe since it allows you to best detect characteristic features in fracture-filled diamonds.
Laser Drilling- This is another procedure that allows you to enhance the clarity of your diamond. This treatment removes the dark inclusions within your diamond. With this treatment, a laser beam is drilled into the dark region of the diamond which essentially vaporizes the inclusion. If not, the inclusion can be dissolved with bleach or acid. As a result, the diamond appears to have a hole that looks like a white dot when viewed face-up and a thin white line from the side view. This treatment is permanent and is more accepted than other diamond treatments.
With this type of treatment, the dark spots will not reappear, the clarity of the diamond remains intact, and the internal character of the diamond is not compromised. Also, diamonds treated in this manner are just as durable as untreated diamonds.
Coatings- Diamonds are usually coated to enhance their clarity grade or to change their color. Usually chemical compounds, nail polish and enamel are used to coat the diamonds. This procedure is not permanent. To determine if your diamond is coated, it's best to use magnification, solvents or color filters.
Irradiation and Heating- With this treatment, light yellow and brown diamonds are irradiated to produce a wide range of colors that are found within the visible light spectrum. Afterwards, the diamonds are heated at about 800 to 1000 degrees Celsius to improve the color of the diamond. Some irradiated diamonds are stable after undergoing this treatment but some are not especially if they come in contact with a jeweler's torch. This form of treatment can be detected under magnification.
High Pressure High Temperature (HPHT) Treatment- This particular treatment was first introduced in the 70's. Until 1999, this treatment has become useful for changing inexpensive brown colored diamonds to colorless diamonds. The benefit of HPHT treated diamonds is that they are less expensive than fancy colored diamonds. One of the disadvantages to buying an HPHT treated diamond is that over time it's not able to withstand abrasions and chipping.