What diamond clarity characteristics to look for to ensure safe diamond investment in South Africa.

Diamond clarity is determined by the amount of internal imperfections or flaws called inclusions and external imperfections called blemishes that are visible to the human eye under various magnifications. Diamond clarity is one of the four characteristics that give value to a stone. Other categories that create value and beauty are cut, colour and carat.

  1. A flawless diamond has no visible imperfections even under 100x magnification. The abbreviation for Flawless Diamond is to “IF” for internally flawless and “FL” for Flawless. Flawless diamonds cost more and should only be paired with the best colour called colour “D” to ensure a safe investment. A diamond with clarity of VS2 will look identical to a flawless diamond to the naked eye but will cost less.
  2. Very, very slightly included (VVS) diamonds are the second highest clarity range and have an abbreviation of “VVS1” and “VVS2”. VVS2 have slightly more imperfections than VVS1 but both have inclusions that are very difficult to see even under 100x magnification. This diamond clarity grade looks identical to VS1 and VS2 to the human eye and should not cost much more as a result.
  3. Very slightly included diamonds are called “VS1” and “VS2”, they have small imperfections that are hard to see under 10X magnification. Diamonds with “VS” clarity are great investments, and should ideally be paired with a high grade of diamond colour. Cape diamonds sells a lot of colour “D” diamonds that are paired to “VS” clarity stones. Colour “H” clarity VS2 are also popular. The best way to view these inclusions is to use a jewelers magnifying glass called a jewelers loop.
  4. Slightly included (SI) diamonds are usually great value as they look almost identical to flawless diamonds but cost a fraction of the price. However, some of them have tiny visible inclusions that some people claim to be able to see. GIA has a very strict rating system as a result “SI1”- “SI2” diamonds are generally good investments. Always ask your jeweler if it is an eye clean stone. These are very popular in South Africa due to the affordability and resale demand.
  5. Included diamonds fall into three categories I1, I2, and I3. I1 has the least amount of inclusions and I 3 has the most. I1-I3 diamonds are a very bad idea and have virtually no resale value. Their flaws can be seen by the human eye at a distance and will create an embarrassment for the person wearing the visibly imperfect stone.

See the video below for more about diamond clarity characteristics.



GIA diamond grading laboratories have classified inclusions into various types and each type has a symbol. Some inclusion types are better than others as they are less visible. The location of the inclusion affects the value as diamonds in the SI2 range with imperfections in the middle of the table are less desirable.

You must know about inclusions to get a good deal with SI1 and SI2 diamonds. Fortunately, Cape Diamonds hand selects these diamonds based their resale value. We do our best to avoid visible black marks in the table and we also avoid milky stones.

The diamond size and shape affects how easy it is to see the diamond inclusions. An Si2 round diamond has very little chance of having a visible inclusion while a 5ct round diamond may well have visible inclusions. As the diamond size increases, so do the inclusions. To be safe, any Si2 diamond over 0.8ct needs conformation from the jeweler that there is no large black mark in the table. Probably about 5% of 1ct round Si2 diamonds will be considered non-eye clean. They will cost a fraction of the price and should be avoided.

The position of the inclusions, relative to the shape of the diamond determines how visible the inclusions are. As mentioned above, when a diamond has a black mark in the table of the stone it is more visible. The table is the largest facet on the diamond and is basically an open window into the heart of the gemstone.

Emerald cut diamonds have the largest tables and additionally, they have facets made up of parallel lines that reflect the flaws in multiple windows. An emerald cut diamond has large table to girdle ratio of 61 – 72 percent while a round brilliant cut is only 53 – 61 percent. When purchasing an emerald cut diamond, be sure the inclusions are in the corners or best select a VS1 or VS2 stone.

The GIA inclusion symbols can be classified into natural and man-made. Man-made inclusions are diamond flaws or imperfections created in the polishing process or after, through wear and tear.

The South African diamond below has virtually all types of inclusions and blemishes within a single stone. The two natural flaws to worry about are large black crystals in the table and clouds that occupy a large portion of the stone.

Man-made inclusions are a definite no! Avoid at all costs as they have zero resale value. A diamond with chips should never be purchased, but rather the chips should be polished out. Bearded girdles and bruises are less noticeable and more acceptable types of man-made marks.

Natural inclusions are marks that formed in the diamond deep in the earth, under huge pressure and high temperature. Most of them are non-visible in Si2 clarity grades and higher. Imperfections to avoid are large black crystals and clouds. Other less noticeable spots would be Natural, Pin Point, Indented Natural, Twinning Wisp, Cavity, Needle, feather, internal graining and white crystals.

A Natural

A “Natural” graded inclusion is actually often a sign of good polishing practice as a portion of the original rough diamond crystal surface still remains and shows that the diamond cutter polished the rough stone to maximize the weight. Naturals are often found on the girdle of the stone and present very little to worry about in clarity Si2 diamonds and above as they cannot be seen by the naked eye. We give it an 8/10 for an inclusion rating, with 10 being the best and 1 the worst.

Indented Natural

An indented natural is a natural that has a slight cavity attached to it that goes into the stone. They are mostly on the girdle of the gemstone. They are usually not worth worrying about, but they can accumulate microscopic dust that may make the indent darken over time and may therefore require some maintenance. It scores a 7 out of 10.

Bearded Girdle

Bearded girdles are a sign of poor diamond polishing. The diamond cutter was likely rushing and pushing the diamond too hard on the wheel while the diamond was being bruited (rounded). Bearded girdles can affect the overall polish rating of the stone. They get a 6/10 score.

Pin Points

Pin Points are microscopic specs in the diamond and nothing to worry about. The name says it all, they literally are pin point inclusions. Pin points can sometimes be used to identify the gemstone under 20 x magnifications. They get an inclusion high score of 9/10. They are the best imperfections to have.


Crystals can be good or bad, depending on size, color and location.

White crystals are hard to spot, while black crystals are easily seen. The size of the inclusion determines how visible it will be in an SI1 and SI2 stone. A black crystal in the middle of the stone will be visible in Si2 diamonds over 0.7ct.

Diamonds with large black marks will naturally cost less. Some people are lucky to find an inexpensive Si2 diamond with a large mark on the side. They know about ring design and understand how the claw of the engagement ring can conceal the blemish. Small black crystals are not a great concern as many of them cannot be seen without magnification. Large black crystal inclusions get a rating of 3/10, white crystals 7/10 and small black crystals get a rating of 7/10.

The main point is that the diamond’s flaws must not be blatantly visible when she shows off the ring to her friends. A few minor black or white spots are no big deal. But a large black crystal in the middle is a definite no. Always ask your jeweller if the diamond has large black crystal inclusions in the table.

Twinning Wisp

When diamonds are growing and forming under the earth, they may develop a mix match of micro inclusions in a wispy curved line due to the underground pressure and heat. These inclusions are generally white in colour and are of little concern in Si2 and above stones. They score a 7.5/10.

Laser Drilled Holes

Some diamonds have large drilled holes that are visible from a distance with the naked eye. They look terrible and are unsalable. These inclusions can be disguised so you need to be careful: After the imperfection is created (often in order to drill out other imperfections), acid may be used to turn the dark inclusion white or a transparent gel can be injected into a large fracture to make it seem less visible. Laser drilled diamonds are a definite no-no as they have lost their natural quality and are damaged. They get a score of 1/10. Stay away!


Clouds are made up of hundreds of tiny pinpoints that are grouped together. They are always white and are not worth a worry if they are small. The problem occurs when the cloud covers a large portion of an SI1 or SI2 gemstone.  The stone may get a milky look. Small clouds get a rating of 7/10 but large clouds score a 2/10. Ask your jeweller if the diamond is milky.

Milky stones lack sparkle and are a bad investment. The GIA diamond certificate cannot indicate how milky the diamond is. You must see the diamond or trust the source when dealing with clouds.


The name cavity says it all. Cavity imperfections open up the surface of the gemstone. They are mostly on the girdle and can collect dust over time making them more visible. If this happens the diamond can be cleaned when taking into a jeweller to get your engagement ring polished.

In Si2 diamonds and above cavities are okay and have a rating of 7/10 as they are normally on the sides. A large cavity in the middle of the table is not a great choice.


Some second-hand diamonds may have been knocked very hard by the wearer while in the ring. The impact could have caused a bruise. Similarly, if you tap lightly on thick glass with a hammer you may see how a bruise is formed. Bruises are not that easily seen but do indicate that the diamond is second hand. They get a score of 4/10.

A Chip

A chip in the diamond is likely a sign that the diamond is second hand. Jewellers may also chip the stone when setting it in the ring. Always inspect your diamond after it is set to be sure that it does not have any chips. Chips must be polished out as they are unacceptable man-made imperfections. Avoid as the rating is 2/10


Needles are very fine lines in the diamond. They are so thin it is usually impossible to see them with the human eye. Under magnification they are mostly white. Needles are most often not terrible inclusions and get a score for diamond clarity of 7/10.


Feathers are white inclusions that resemble a feather in appearance. They are very hard to see due to their colour and slim dimensions. Diamonds graded Si2 with feathers are perfectly acceptable. Feathers are rated 7/10.

Internal Graining

Internal graining is one of the least problematic inclusions to find in a diamond. It is usually unseen to the human eye as the parallel lines are so small. Internal graining is related to the growth lines of the rough diamond and often carries the same geometries and angles as the original diamond crystal. Internal graining gets a high rating of 9/10.


When a diamond has a rear knot it is actually a diamond crystal within a diamond that does not have the same growth lines or internal graining. Is it a bit like a knot in a piece of wood that is caused by the branch growing out of the trunk. Knots are not easily seen as they are not dark like the ones found it wood but rather similar in colour to the other larger crystal they are attached to. Knots are mostly acceptable and get a rating of 8/10.

Problematic diamond inclusions.

99% of Si2 diamond inclusions are acceptable but some are potentially disastrous. Here are some final tips to summarize what to look out for:

  1. Clouds are ok when they are small, but large clouds make the diamond look milky. Always ask if the stone is milky or compare it to other diamonds to see if the sparkle is perfect.
  2. Black Crystals are very noticeable when in the middle of Si2 diamonds. Ask the jeweler or look at the stone to ensure no black in the table facet.
  3. Diamonds with laser drilled holes should never be purchased.
  4. Chipped diamonds should never be purchased.