Diamonds are renowned for their clarity, their transparency. Most diamonds have some internal flaws; the naked eye can see some, and some are only visible under magnification. The higher the degree of clarity, the more the diamond will cost to buy.

The most commonly used grading scale, devised by the GIA (Gemological Institute of America) runs from Flawless/IF to I3.

Flaws inside the diamond are called inclusions, those on the surface of the gem are called blemishes.

The grade a diamond receives is based upon five factors:

1. Size of the inclusion, this can be relative to the size of the diamond, but larger inclusions lower the grade.
2. Type of the flaw, is it on the surface or internal, is the durability of the diamond affected?
3. The number of inclusions; the greater the quantity, the lower the grade will be.
4. Location of the inclusion (those nearer to the centre of the table facet tend to affect the clarity rating more than others).
5. Relief, the ease with which the inclusion can be seen.

The grade a diamond receives is based upon five factors:

To maximise the sparkle of a diamond, the surfaces must be as smooth as possible; this is called 'polish'. Polish is reported in the diamond grading report. For any diamond used in jewellery never choose a diamond whose polish is reported as 'poor', no matter what grade the clarity might be.

Top Diamond Buying Tips

Diamond Shapes And Clarity

Some diamond shapes hide flaws better than others. Emerald and Asscher cut diamonds make inclusions visible. Round brilliant, oval, pear and marquise can conceal inclusions, making it possible to choose a slightly lower clarity grade.

Choosing Carat And Size

If you are choosing a diamond based on size and price, a clarity grade of SL1-SL2 is generally a good choice.

Visible Flaws (Inclusions)

If you are budget conscious, choosing a diamond that is free from inclusions visible to the naked eye is a good option. Clarity grades VS1-VS2 will appear almost perfect to the naked eye and offering a decent saving over the FL-IF grades.

Better Value For Money

If you need to save a little money, look at diamonds with SL1 grade clarity. There will be small inclusions, but they will not be obvious. The diamond will look very good.

Diamond Clarity Grade Descriptions

Flawless-IF

Diamonds of this grade will have no inclusions or blemishes that can be seen at 10x magnification. There may be slightly visible surface blemishes at 10x magnification.

VVS1-VVS2

At this level, there will be very tiny inclusions that even a skilled diamond grader will have difficulty seeing at 10x magnification.

VS1-VS2

Diamonds of this grade will have microscopic inclusions.

SI1-SI2

There will be inclusions that are quite easy to see at 10x magnification. In some cases, inclusions might be visible to the naked eye.

I1

At this grade, inclusions will be evident under 10x magnification. Some inclusions might be visible to the naked eye. Check that the inclusions at this grade are not severe enough to be likely to affect the durability of the gem.

Diamonds Are Natural, Inclusions Are Normal

Diamonds are a natural material. Inclusions are created naturally during the formation of the gem. Rather than regarding inclusions as flaws, think of them as being a part of the uniqueness of your diamond.