Laser Drilling

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When a diamond has a dark coloured inclusion, laser treatment can remove it. The process is simple. The diamond is laser drilled until the laser strikes and valourises the inclusion.

The Marquis shaped diamond on the right had a large black inclusion removed by laser drilling.

Note that the picture on the right is subject to darkfield illumination. After the inclusion is removed, you will not be able to see the canal and the space where the inclusion used to be, with your naked eyes. The imperfections are now colourless. Hence, it would be possible to create an eye clean diamond out of something that nobody would think of wearing.

Detecting Laser Treatment

Laser treatment is very difficult to detect if the inclusion removed is very close to the surface, like for the diamond above.

The laser drilling is usually done perpendicular to the diamond's surface, so as to reduce the visibility of the drilled canal.

The picture on the right is a microscopic picture of the after-effect of laser treatment, for the diamond above. Note that when seen from an angle, the canal from the surface, to where the inclusion used to be, can be seen. Since this inclusion was close to the surface, the canal is short. Hence it is difficult to detect the laser treatment. A high powered microscope is therefore needed.

On the left, is a picture of a much longer laser drilled canal, which would be easier to detect.

Laser treatment is usually not noticeable when viewed from the top of the diamond because the canals are all pependicular to the surface. Hence the canals do lower the clarity of the diamonds.

However, we must be careful to check the sides of the diamond, to make sure that these canals are not visible and offensive when viewed from an angle. Remember, if the diamond is not tilted, you will not be able to see the canals.

How would I know if a diamond is laser treated?

Not unless you know how to use a microscope, chances are, you will not know if the diamond is laser treated.

You should only buy diamonds from honest and knowledgeable jewellers who will tell you if the damond is laser treated BEFORE you even ask them. If they do not tell you, it pays to ask, or you may risk paying more than the fair price for the diamond.

Is laser treatment permanent?

Laser treatment is permanent. The coloured inclusions are permanently removed. Also, the canals will become part of the imperfection of the diamond permanently. As such, GIA will certify laser treated diamonds (unlike fracture filled diamonds).

Does laser treatment affect the price of a diamond?

If done well, laser treatment will improve the clarity of the diamond permanently. If such a diamond is sent for grading, it should enjoy a higher clarity grade. Consequently, the price of the diamond will increase in accordance to its improved clarity grade.

However, be aware that the price of a laser treated diamond is lower than their unenhanced counterpart with the same quality. For instance, a 1ct D coloured SI2 (Read the 4Cs for description on these qualities) diamond that has not been treated will cost more, compared to a 1ct D coloured SI2 diamond that has been laser treated.

Should I be considering a laser treated diamond for my Proposal Ring?

Yes you should. If the laser treated diamond is within the clarity grade you are comfortable with, it is good value since it is cheaper.

Laser treatment is permanent, so the clarity is permanently enhanced. Hence, there is no reason why you should be prejudiced against laser treated diamonds.