Laser drilling- what is it?There are a number of methods of minimizing natural inclusions in diamonds.
The two primary methods are "
Fracture filling", and "
Laser Drilling"
The first method is more intrusive and far less desirable than the second.
GIA will not grade a stone that is fracture filled- which is also known as "Yehuda process"
The reason it's considered worse is that it involves injecting plastic in a fissure in a diamond.
It's similar to a process used on car windshields- where they repair a crack.
In diamonds, the process results in a slightly hazy appearance- and sometimes a rainbow effect can be seen.
Another problem with it is that it's not necessarily permanent.
For example if the stone is heated as is common during jewelry manufacture or repair, the plastic can melt causing the stone to return to it's former condition- where the imperfection is clearly visible.
Laser drilling is a process used on diamonds that may have an obvious black spot.
A laser is used to drill a channel to the carbon, then the diamond is boiled in sulphuric acid which bleaches the black spot into a white one.
GIA will grade such diamonds, and indicate the drill on the report.
The process is permanent.
Another positive aspect to this process is that it's fairly easy to spot, sometimes with a loupe, sometimes naked eye. This is a good thing compared to Yehuda filling which can sometimes be difficult to spot. The idea is that honest people in the trade do not support selling of treated stones going undisclosed.
Here's an example of a drilled stone.
it's a 2ct Daussi cushion.
You may notice a few white spots in the center of the diamond- along with the a white line
The white line is the channel drilled by the laser- that's the evidence left making this treatment easier to spot.
In terms of value it does not increase, or decrease value- but it may make a stone more attractive.
This stone has a single drill , however there are also cases where a stone has multiple drill channels.
colored diamonds
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