What is a treated diamond?
A natural diamond that is enhanced for its color, clarity, and brilliance by several man-made processes like HPHT, irradiation, fracture filling, laser drilling, etc. is a treated diamond.
Now we know about the fully natural earth-mined diamonds and diamonds that are natural but treated in any certain ways, or we can say them as enhanced diamonds. Here we will discuss the later ones and the various treatments done on them.
From times the researchers and technologists have been tweking with this beautiful gemstone of earth, now with time and improvements in technology new ways of sophisticated treatments to improve the appearance of a naturally occurring diamond are practiced for the trade.
The process developed in the year 1950 is to grow an immature diamond (diamonds that are not fully crystallized) in a lab, and by applying a certain amount of controlled pressure and temperature that mimics naturally necessary temperature and pressure, the carbon needs to convert into a diamond deep within the earth.
HPHT is an irreversible process and is applicable for both premature and developed diamonds; in the former, the embroyo carbon molecule transforms into a fully grown, strong stone by HPHT, making it worthwhile from its rough form. Also, in a mature diamond, sometimes the minor flaws, which are in the form of undeveloped crystals, turn into diamond crystals, providing more even clarity and shine to the stone.
Color alteration of HPHT diamonds: Diamonds usually come with minor shades of yellow, brown, or green that diminish towards colorlessness by HPHT treatment, or a fancy premature color present formerly in the stone can become complete after the treatment.
Always a good clarity diamond is selected to be enhanced by HPHT because diamonds with inner fractures tend to tear apart when subjected to an extreme amount of pressure, which is 900,000 pounds and heat around 1500 degrees Celsius per square inch, so a minor to moderate transformation only happens to an already developed diamond with HPHT by structuring the left-over raw crystals to diamond, but for a premature diamond the changes happen fully, resulting in a lab-grown diamond.
The treated diamond is a natural diamond, and the enhancement is permanent in nature, so pioneer labs will certify it as a natural diamond but will always mention in comments about the treatment the natural diamond has undergone, stating it as a natural HPHT-treated or any other type of treated diamond.
There are various ways to identify HPHT treatment; one is by reaction to UV waves, which will be stronger with shorter-wave UV instead of long-wave UV; the other way is the formation of metal within the crystal, which will never happen if the diamond is natural, so the presence of metal is the way to identify a HPHT diamond.
These are color-modified diamonds by irradiation, which is the cause for any color change that happens in a diamond either in the natural condition over a course of millennia or done in a laboratory in a very short period of time in a few hours to months. It happens due to the exposure of a diamond to radioactive waves, including alpha, gamma, and beta rays, which involve thumping the mobility of carbon atoms in the diamond. The three mentioned rays, which are formed of electrons, protons, and neutrons present in the cell of an atom, are selectively bombarded on a diamond in a necular reactor to color treat the diamond with radiation.
Naturally, the alpha rays provide a slight change in the color of the stone form, giving it a tint or light shade towards green remaining near the skin of the crystal, but the gamma and beta rays provide a more intense penetration and significant color change.
The discovery of the lab irradiation process is not new but dates back to a century and a quarter when, in 1904, an English chemist 'Sir William Crookes' discovered that a diamond's color is changed when exposed to radium salts, but with his experiments, the color changes remained near the surface area and not penetrated within; also, the stone became so radioactive that it was not suitable to wear.
Annealing process: post-irradiation treatment, the diamonds are sometimes heated at certain specified temperatures to alter the color of the diamonds further, which is called annealing.
Methods of Irradiation:
Out of four irradiation treatments, electron bombardment is a common irradiation treatment done on diamonds where Van De Graaff generators are used for electron bombardments on diamonds producing green, blue-green, or blue color, and these stones, if further heated to a temperature in the range of 500-9900 degrees Celsius, convert stones to pink, brown, yellow, orange, etc. The color penetration by this process is not deeper than 1 mm from the surface.
Cyclotroning is a least-used method where proton and neutron bombardment using cyclotrons is done on the diamond, producing green-blue and green color in the stone, which just remains on the surface. This is very uncommon as done direction-centric, and as all stones vary in cut, the side from where the diamond is cyclotroned will have deeper color, like if done from the top, it will form a deeper color ring on the crown, and if done from sideways, the side will catch more color compared to the opposite side. The stones, if further annealed to 800 degrees, will turn them yellow, yellow-brown, or orange-yellow.
Neutron bombardment via nuclear reactor is the most common irradiation treatment performed for color-altering a diamond, producing blue, green, greenish blue, gray, or black diamonds, which further, if red heated to 500-900 degrees Celsius, produces fancy pink, yellow, orange, and dark brown colors. Color is holistically penetrated in the stone, similar to what the gamma rays do.
Gamma-ray bombardment by exposure to cobalt-60 is the cheapest way of color treating diamonds but is seldom used due to the long duration of a few months it takes to color change the stones. Mostly yellow-tone stones are used in this, and the result comes as blue or blue-green, which is fully penetrated in the stone, and these diamonds are not further annealed. The diamonds that have any tint of blue will post-treatment get a greenish tint.
It is a treatment to remove an inner trapped inclusion in a diamond, like foreign crystals, black carbon, etcetera, by drilling a microscopic whole through the surface to the inclusion site, making a passageway, then the stone is boiled in some chemicals to melt the inclusion, or even the inclusion is burned by laser sometimes to improve the clarity of the diamond.
A diamond without any eye-appearing inclusions is rarely found, so the people in the trade must always be wanting to find ways to remove inclusions from the diamonds, and this is an easy and commonly adopted method for removing unwanted inclusions like lines or pin point natices from a diamond. Sometimes a very good stone may just have a single ugly, unaccepted inclusion, so it's a good accepted way to drill out the isolated inclusion by the method, making the stone look more flawless.
The drill made by the laser is just 20 microns in diameter; it is even much thinner than a human hair strand. There is then another way to do laser drilling, which is uncommon, where instead of laser burning the channel to the inclusion site, a microplane is burned across the diamond until it reaches the inclusion, but the hollow space created this way is thicker than the laser drill but is more natural-looking and not easily observable.
The laser holes are tough to be deduced by naked eyes, so a microscope or an eyeglass can be used for it. Laser is a permanent treatment on a natural diamond, and thus laboratories like GIA (the Geological Institute of America) will mention the treatment as 'laser drilled' on a natural diamond report. If the diamond has any filling used similar to glass resin, then the GIA, American Gem Society, will not certify those stones as the fracture filling is not a permanent process, and just by boiling the diamond, it will again come in the pre-treated state.
A single drill will not affect the strength of the stone, but if there are multiple drills in a single diamond, it will alter the bonding of the stone, making it vulnerable; those stones falling in the category of fracture-filled diamonds are generally weak because they have hollow spaces within.
The price of these diamonds can remain slightly to significantly low on the basis of the treatment applied and its intensity. For example, a natural yellow diamond of one carat is $2500; in the same clarity and color, a HPHT-modified diamond can come at $1000 or less.
Example 2: A natural VS1 diamond of 1 carat comes at $4000 now. If the clarity is enhanced of an I1 diamond by laser drilling and fracture filling to make it VS1, then it can come in around half the price that is $1500-$2000.
We are dealers and manufacturers of irradiated diamonds, HPHT diamonds. All the stones will be certified natural with treatments and at best business prices. Buy blue, green, yellow, red, pink and other color treated natural diamonds with us.
We supply diamonds worldwide to jewellers, diamond dealers, jewellery designers, etc. Doorstep shipping all over globe to USA, China, Europe, Russia, Australia, India, etc.
Someone's value is determined by the trust other people hold in him/her, We here at Jewel Fields believe that the amount of trust people have in us should be more than what they have in themselves.
