What is hidden inside a diamond? 2/2
However, the purity characteristics we discussed in the first part are not so much appreciated by common people as they are for gemologists: it is true that the more a diamond is devoid of it, the higher its carat price will be high.
In order to determine the value of a diamond on the basis of its purity, a scale was invented which is strictly followed by gemological institutes, which is based on the gems’ observation through a 10x magnification loupe and on the “ease” of finding such inclusions by an expert and trained eye.
Purity scale of the American Gemological Institute (GIA): starting from the left the diamonds without inclusion, to the right the number of inclusions and their position gradually increases and concentrates towards the center.
Photo credits: 4cs.gia.edu
If, after careful analysis with the appropriate light conditions, the analyst does not find any inclusion, then the diamond will be classified with IF – or Internally Flawless – or VVS – Very Very Slightly Included. In order to discriminate between the two terms, it will be necessary to use a gemological microscope, which will allowed the operator to say whether some small inclusion (such as some pin points or some tiny feathers) is actually present inside of the diamond examined.
What is the difference between the two diamonds in the picture? They are both 1.00 ct, G color and excellent cut.
On the left a VVS while on the right a VS, with a price difference of about 15%.
Photo credits: 4cs.gia.edu
Just after the VVS diamonds, on the purity scale we find the VS diamonds – Very Slightly Included – which show some more inclusions than the VVS inside them: already through the loupe you can find small feathers or clouds in a semi-central position.
SI diamonds – or Slightly Included – instead, will appear, to a trained eye, included in the loupe: you can observe small crystals (sometimes even colored), numerous clouds and feathers that could disturb the brilliance of the gem.
If these inclusions can be observed even without the use of the loupe, then we have an I – Included diamond – in which the characteristics of purity will inevitably compromise the brilliance, beauty and hardness of the gem itself: large crystals can be observed, important fractures and clouds. These diamonds are difficult to set and to handle since the inclusions make even the hardest product that nature has ever created fragile.
SI2 diamond, color D: moving clockwise between the most obvious inclusions we have:
2:00 am, small crystal that is reflected three times
4:00 am, crystal and feathers
7:00 am, black crystal
11:00 am, group of crystals and feathers.
Photo credits: www.indiamart.com
Obviously, since it’s almost impossible to confine a diamond in such large categories, it was decided to add sub-categories to each macro group of inclusions, in order to be more accurate in the description.
It’s very important to consider purity, together with color, cut and carat weight when we want to buy a diamond, since it’s often necessary to find the right compromise between these four parameters in order to find the desires’ gem.