Making COLORed DIAMONDS
In nature, diamonds are created at extremely high temperatures and pressures in the mantel of the Earth, at a depth of around 140 to 190 kilometres. Trace amounts of boron will create a blue diamond, while trace amounts of nitrogen can create a naturally yellow diamond, and exposure to natural radiation can create green diamonds.
In the laboratory, processes which would usually take thousands of years can happen in a mere few hours. The processes usually used today are irradiation, HPHT and coating. They also happen to be the three processes we use here at LOTUS COLORS, INC..
What it does? - Natural color in a diamond comes from the presence of trace impurities in the stone or structural irregularities at its atomic level. The reason a diamond looks the way it does is all down to the way its atoms are arranged. Irradiation activates the diamond’s color center – a network of atoms and subatomic particles that work in a way that gives each diamond a particular color. Irradiation promotes changes in the stone’s atomic structure in the laboratory – with the same result: the diamond gains color. Irradiation doesn’t actually ‘give’ a diamond color, therefore, but rather simply unlocks its color potential.
Irradiation - Currently the safest way to irradiate diamonds is by using a machine known as a linear accelerator. This fires a pulsed beam of electrons at the diamond, which then disturbs the electrons of the diamond itself, causing them to be knocked loose and ‘captured’ by other atoms. The light absorbing structure of the gem is changed and, as a result, so is their color. This process is known as low energy electron bombardment.
Annealment - Exposure to electrons gives diamonds a greenish blue or blue colors. In order to get the whole multitude of colors, irradiation is followed by heating to an extreme temperature of around 450 C/850 F and upwards. We call this ‘annealment’ as it is done in an oxygen-free environment. This causes the stones’ atomic structure to rearrange yet again, resulting in a range of new colors. Annealment is a process that mimics nature, since natural heating in the right environment can alter a diamond’s color as well.
Here at LOTUS COLORS, INC., we use only low-energy electron methods of irradiation and annealment. More powerful methods using protons and neutrons can work faster, but these types of treatment may result in radioactivity in the diamond, so they’re best avoided.
Colors Manufactured by LOTUS COLORS, INC. using Irradiation - All our colors other than Ice Pink are manufactured using Irradiation – Aqua Blue, Sky Blue, Ocean Blue, Royal Blue, Ice Green, Emerald Green, Forest Green, Canary Yellow, Golden Yellow, Rose Pink, Purplish Pink, Purple, Orangish Cognac & Reddish Cognac.
Tips on Diamond Care - Irradiated Color enhanced Diamonds, like all diamonds, are legendary for their hardness and durability, resistant to general wear and tear, and not subject to change over time. Therefore, they require no special attention in daily use, until and unless they’re subjected to temperatures above 450°C (850°F). Generally, the only time this happens is at the jeweler’s bench, usually during the resizing of the ring.
The High Pressure, High Temperature (HPHT) process is designed to precisely mimic the natural conditions in the mantel of the Earth where diamonds are created. The process allows the natural trace elements within a diamond to relax and to display their natural color. Highly sophisticated machines expose the diamonds to heightened heat and pressure resulting in the change of the color of the diamond. When it emerges from the machine, the diamond is initially covered in a frosty outer layer. After polishing, their newly attained beauty is revealed. Only diamonds of very high clarity can be used for this process, as any small feathers in the diamond will result in worsening or even chipping out of the diamond during the HPHT process.
Initially the primary colors created using HPHT were white, yellow, green & orange. Recently with the combination of both HPHT and irradiation, we have been successful in manufacturing some Rose Pink, Purplish Pink and Purple diamonds in limited quantities.
Colors Manufactured by LOTUS COLORS, INC. using HPHT - Canary Yellow, Golden Yellow, Rose Pink, Purplish Pink & Purple.
Tips on Diamond Care - Among the three processes, HPHT enhanced diamonds require the least care. They like all diamonds, are legendary for their hardness and durability, resistant to general wear and tear, and not subject to change over time. They require no special attention in daily use, and can also be subjected to high temperatures.