There are many methods of enhancing diamond colors. Some are to whiten white diamonds and others are to enhance the color with diamonds with not-so-good color. At A2ZDiamond we use color enhancement for treated fancy colored diamonds only. We do not use any methods to raise the grades of white diamonds. Such as enhancing a “G” color diamond to “E”. The different methods we use to enhance the color in our diamonds are HPHT, Irradiation, Heat and Surface Enhancement. All our items are clearly labeled as Enhanced on our item description.
High Pressure, High Temperature (HPHT)
HPHT is a process developed by General Electric in 1999 to color treat diamonds. This process puts over 60 kbar (nearly 1,000,000 psi) of pressure on the diamond at around 1400°C (2550°F). Diamonds treated with HPHT can transform into many colors including to pinks and blues. HPHT can also be used to create white diamonds; however A2ZDiamond will only use this process to create fancy colored diamonds. This treatment is permanent and will not be affected by cleaning or heat from setting repairs.
Irradiation treatment involves exposing the diamond to electromagnetic rays to release electrons from their normal location to a more desirable location changing its color. Neutron bombardment and electron bombardment are the two main irradiation methods practiced today. Diamonds treated by irradiation produce many brilliant colors such as green, yellow, blue and reds. This color treatment is permanent and will not be affected during cleaning processes. However, blue or green enhanced colors could change to a yellowish color if high heat, 300°C (572°F) or more, is used during setting repairs.
Surface Enhancement (SE)
Surface Enhanced diamonds are chemically treated to change the color of a diamond to Brilliant colors. This is done by coating the diamond surface with a metal halide. A similar technique used to coat some camera lenses that create the blue reflection. This method can produce vibrant pinks and cognac reds. Care should be taken with surface enhanced diamonds. The coating can wear out during heavy cleaning, color fade by after long use or heat from setting repairs.
Heat Treatment (HT)
Heat Treatment or 'annealing' is done using a combination of chemicals (beryllium, borax, lead, tantalum) and heat to change the diamond's color. Heating or "cooking" the diamond is done at temperatures ranging from 450°C (842°F) to 1850°C (3362°F) for 2 to 12 hours or more. We only use this process to create our black opaque diamonds. To check if a diamond has been heat-treated, one way is to look for the presence of small fractures within the stone that appear around natural mineral inclusions. This treatment is permanent and will not be affected by cleaning or heat from setting repairs.
Clarity Enhancement or/and Feather Filled Diamonds
During the process of clarity enhancement, a microscopic amount of material is inserted in where the inclusion is. This material has the same optical properties as the diamond. When light enters the diamond at one spot and is emitted through another the direction of the ray does not change or reflect in another direction. On the other hand, when passing through an untreated diamond with inclusions the ray of light hits the inclusion and reflects in various directions. This is why we can notice inclusions in the diamond and the stone does not look clear. When passing through a treated diamond, light goes straight through the natural inclusion since the filling used has the same optical properties as
the diamond itself. The ray of light “thinks” it is passing through the same material (the diamond) and carries on in the same direction. After a thorough research the Gemological Institute of America (G.I.A.) confirmed that usual wear cannot have any impact on a diamond. Only open heat exceeding 1500 °C, strong acid, strong alkali or re-cutting could damage an enhanced diamond.
Should you have any further questions or concerns regarding diamonds, gemstones, precious metals and/or A2ZDiamond's jewelry selections, please feel free to reach us at contact@A2ZDiamond.com