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Learn in detail about Diamond Cut.
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Diamond Polish and Why Is It Done?

The shimmering and enticing diamonds that everyone covets do not naturally look the same when they are mined. These much desired sparkling treasures look like ordinary pebbles until they passes through the hands of expert diamond cutters and polisher. Meticulous efforts are put in by many skilled professionals to bring out the latent beauty of the diamond. The natural crystal is first analyzed, cleaved and then proportionately cut into facets. It is given a shape that will best bring out the beauty of the stone and finally the cut diamonds are polished for a smooth and brilliant finish.
Technically the person who transforms these natural crystals into a brilliant precious stone is called a gem cutter or lapida. The term ‘Polish’ in the diamond industry refers to the degree of ‘polishing lines’ that become visible on the surface of a polished diamond with or without the use of 10X magnification. An intensely polished diamond reflects and disperses light falling upon it which makes the diamond shine radiantly.

How are Diamonds Polished?

Diamonds after cutting are smoothly polished to bring out their brilliance. The stone is placed on the polishing wheels which have minuscule diamond crystals fixed on it.  During the polishing process the diamonds are dipped in a mixture of olive oil and diamond-dust to keep them moist. Not all diamonds are polished to the same level; the extent to which a diamond is polished largely depends on the diamond quality and the effects desired. Expertise and the nimbleness of the craftsmen play a crucial role in extorting the beauty and brilliance of diamonds.

Do Laboratories approve Diamond Polishing?

The reputed laboratories like AGS and GIA Gemological Institute of America that is the world’s foremost gemological authority approve of diamond polishing. These labs meticulously consider diamond polishing while grading a diamond. Gemologist use the 10X loupe while grading the diamond polish as excellent, good, fair, poor etc.

Polish Grades for Diamonds

Polish plays a pivotal role in determining the brilliance of a diamond, so it is pertinent to opt for a diamond that is laboratory certified with good, very good or excellent polish. Diamonds which have been graded poor to extremely poor polish are less sparkling as they have microscopic polish lines that haze the surface of the diamond. These polish lines lessen the amount of light that is refracted by a diamond.
The following table explains the diamond grades standardized by the reputed labs:-






The diamond finish smooth and flawless


Very Good  

Polish lines extremely difficult to trace under 10X loupe



Very hard to locate the polishing line under 10X loupe



Polish line may be visible under 10 X loupe



Easily visible under 10X may rarely be visible to unaided eye


Very Poor

Polishing lines  may relatively easy to see with the unaided eye


Extremely Poor

Lines quite obvious to the unaided eye

* All the diamonds sold in have been certified by the GIA.

Polishing v/s Diamond Price

Polishing enhances the inherent beauty of the diamond giving the stone that sparkling finishing. It is an extension of the diamond beautification process that does not affect the cost but the brilliance of the diamond. On the other hand a poor polish may rather spoil the beauty of the diamond. However if facets have been created instead of polishing then the price of the stone may be affected as it is a more time consuming process.
It is suggested to always go for EX, VG, G graded diamonds. At Mysolitaire we sell only those loose diamonds that have been certified by GIA, so you need not worry about the polish grades of our diamonds.

Polishing and Treatment

An important fact to remember is that there is a difference between Treatment and Polishing. Polishing is an important dimension of diamond cutting process. Polishing brings out the natural brilliance of a diamond. It is approved by all the acclaimed gem laboratories. Where as irradiation, drilling, oiling, sealing, dyeing, bleaching, painting or coating, foil-backing and fracture filling are some of the methods of treating a diamond. These treatments help in camouflaging some minor faults that a stone might have. These are unlawful practices and a certificate should always mention the type of treatment used to enhance the diamond beauty.  

Did you know?
  • Most of the worlds diamonds are polished in India at Surat and Mumbai.
  • Israel,Belgium,and New York are other major centers where diamonds are polished. Cutting and polishing of the diamonds are also done in South Africa,Botswana, Russia,China, SriLanka, Thailand,Vietnam,and Mauritius.