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Clarity Enhanced Diamond
Clarity Enhanced Diamond

View from Underside
View from Underside

Clarity Enhancement
Clarity is possibly the most important of the factors affecting the quality and price of any diamond.
You might think, therefore, that enhancing the clarity of a diamond would be considered a positively good thing, but this rarely the case.

Good Enhancement
The simple act of cutting or polishing a diamond could be considered to be clarity enhancement, and is obviously highly acceptable. It makes diamonds look much better than when they are first dug out of the ground. Also when a polished diamond contains small imperfections or inclusions near the surface, it is possible to polish away the part of the diamond containing them, and this again is an acceptable aspect of clarity enhancement of diamonds.

Bad Clarity Enhancement - Fracture Filling
The reason we consider most clarity enhancement of diamonds to be bad, is that it is done by filling in surface cracks and fissures. If this could be done with diamond, by vapour deposition, then it would be almost imperceptible, undetectable, irreversible and stable, in which case, we would consider it as quite acceptable, but probably subject to disclosure rules. However, the filling material is not diamond, but usually a type of heavy glass. While we accept the arguments of those who carry out clarity enhancement, and those who actively market such stones, most of whom are probably quite honest, we believe that downstream from these reputable dealers, there are many people who would think nothing of failing to disclose the fact that the stone was enhanced, and we believe such failure to disclose to be fraudulent. If the carat weight of the diamond formed an important part of the contract, then because some of the weight would be non-diamond material, then any weight stated or estimated would be incorrect, having been artificially increased.
Our other main objection is that the filling material has a much lower tolerance of high temperatures than diamond, so that when repair work is needed on fracture filled stones, the filling is very likely crack or melt, leaving the diamond's owner and the workshop in a difficult position, and neither with any recourse unless the original vendor or enhancer can be found, and is prepared to rectify the problem.

There is actually another form of clarity enhancement which we believe to be reasonably acceptable, although it did cause some controversy when it was originally introduced, and that is lasering.
Let's say you have a large or high quality diamond, but one which has a noticeable black or dark inclusion. This can often be caused by iron oxide (rust!), which can occur as an inclusion in diamonds. It can occupy a cavity within the diamond, sometimes in a very thin layer. Using a powerful laser, it is possible to drill a small neat round hole, usually vertically down from the table, and then to inject acid into the cavity. The acid dissolves (actually reacts with) the iron oxide. The resulting iron salt can then be flushed out of the stone leaving a clear cavity in place of one filled with a dark stain. There is of course the addition inclusion caused by the fine laser hole, and it is not usual for this to be filled.
Because there is no addition of non-diamond material, there is no error or deception caused by this treatment in relation to the weight of the diamond, if anything, because a small amount of diamond has been vaporised in the process the vendor has lost some weight, and the buyer has got a diamond of the same external dimensions, but paid for a slightly lower weight.
In our view, it is desirable that lasering should be disclosed, and we would always disclose it as part of our sales procedure, but is probably not fraudulent to omit disclosure, as it can be seen if the buyer wishes to examine the stone, and there has been no addition of extra material.

Don't ask why the two photographs we show of the same fracture filled diamond appear different colours, much of this effect was probably due to a quirk in the photographic process and lighting, although some of it may be attributable to the filling. The main features to observe are the unnatural flashes of colour which can be seen in the top view, and some strange lines which can also be seen. Rainbow flashes of light can be seen in normal diamonds, but those in filled diamonds look different from those in normal stones, so some experience in looking at diamonds is useful.

More About Fracture Filling of Diamonds

Diamond 4C's Tour - Next Stop - Carat Weight

Diamond Glossary - An A to Z of Diamonds the Lowest Possible Price

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