How to Determine Diamond Clarity

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How to Determine Diamond Clarity

Diamonds are prized for their clarity. When light passes through a diamond it looks clear and bright. Diamonds are natural crystals formed under intense pressure, where carbon is transformed into diamond crystal. A side effect of this intense pressure is that irregularities form within the diamond. These irregularities are known as flaws, and they can affect the clarity of the diamond by altering the way light travels through the diamond.

Before buying a diamond, it is very important to know how to determine its clarity, as clarity affects the diamond's value. It is also important to understand the way in which the diamond industry grades diamonds for clarity, as these grades are used to describe the quality of diamonds.

When buying diamonds, whether loose or set in jewellery, it pays to look at as wide a range of stones as possible. The buyer should be familiar with how diamonds are graded according to their clarity. It also pays to shop around. High street jewellers can be expensive. Online retailers such as eBay offer better prices and a wider range of gemstone jewellery, making eBay a good place to shop for diamonds .

Understanding Diamond Clarity

The fewer imperfections a diamond has, the more it sparkles. This is because there are less obstructions to the passage of light through the diamond. Imperfections fall into two categories: inclusions and blemishes.


Inclusions are flaws within the body of the stone. They occur naturally as a result of variations in the intense pressure applied to the stone's structure during diamond formation. All naturally formed diamonds have some inclusions, even if the stones are described as 'flawless'. This is because diamond grades are assigned after the stone is assessed at just 10x magnification. A diamond which appears flawless at this magnification, reveals flaws at higher magnifications, if the magnification is increased to 20x or 30x.

Cultured diamonds, which are created in laboratories, are much less likely to have flaws because they are created under controlled conditions where there is little or no variations in the pressure applied to the stone's structure.

Types of Inclusions

There are several types of inclusions. Buyers should familiarize themselves with the terms used to describe diamond inclusions as they often encounter these terms when shopping for diamond jewellery.


These breaks in the stone look either white or transparent, and can be a serious threat to the integrity of the diamond if the inclusion is large enough. Feather inclusions can sometimes expand if the diamond is subjected to a hard knock.


A separate mineral crystal can form within the body of the diamond. Most often, it is actually a miniature diamond crystal, although it can be another mineral.


A needle is a long, rod-shaped crystal, within the diamond. Its appearance can vary. Sometimes needle inclusions are white, while other times these inclusions can appear as quite dark.


A pinpoint is a tiny, dot-like crystal.


A cloud looks like a patch of white or grey, but is actually a group of pinpoints clustered quite together. Clouds can reduce the clarity of the diamond by interfering with the transmission of light through the diamond.


Unlike inclusions, which are inside the diamond, blemishes are imperfections that appear on the surface of the diamond. They can affect the clarity of the diamond, too, although, they do not affect the passage of light the way inclusions do. Blemishes can form as a result of the cutting process, wear and tear, or they can be natural faults in the crystal structure, created during the diamond's formation.

How to Examine a Diamond

Although these flaws can adversely affect the clarity and brilliance of a diamond, it is not always possible to see them with the naked eye. In fact, only the lowest grades of diamonds have flaws which are visible without magnification. The higher the magnification, the more the flaws become apparent. Normally, for the sake of consistency, diamonds are examined and graded under a 10x magnifier.

The Examination Process

The examination of a diamond is best undertaken when the stone is unmounted, as a mounted stone can have as much as a quarter of its body obscured by the jewellery. The examination should take place when the diamond has been cleaned, and it is best to hold the stone carefully using tweezers to avoid leaving greasy fingerprints on the diamond.

The stone should ideally be examined under a proper gemscope. All good jewellers have them. At the very least, there should be a 10x loupe available, although these are difficult to use. Ideally the jeweller should have a stereo microscope.

What to Look For

While looking for obvious flaws in the stone, the buyer should try to judge the clarity and brilliance of the stone. This is a subjective judgement. They should look both at the surface, and into the depths of the stone, and try to judge if the description provided to them by the seller matches what they are seeing in the diamond. The buyer should understand that all diamonds have inclusions, it is just a question of degrees. If the stone looks clear and bright to the buyer, then the presence of any inclusions need not be a problem.


The diamond should be examined under different light sources, starting with a clear laboratory light, where the colour of the light is a neutral white. They should also examine the stone in daylight, and using a colour grading tray. As with magnifying equipment, a good jeweler should make lights and colour grading trays available to their customers.

Grading Diamond Clarity

In order to avoid costly mistakes, there are internationally recognised grades for diamond clarity. These are as follows:





No flaws at 10x  magnification; flawless

Diamond appears perfect


Very slight inclusions; two grades

Diamond appears almost perfect


Very slight inclusions visible, but not easy to see; two grades

Often good buys; cheaper than VVS1/2, but almost as good.


Slight inclusions, can be seen readily at 10x; three grades

Less expensive than VS1-VS2


Inclusions visible with naked eye; flaws affect clarity; three grades

Some dealers sell these, others do not; fair buys, at the right price.

These grades are often used to describe the quality of diamonds. As with the terms used to describe the different types of inclusions, a buyer should familiarise themselves with the accepted grading system for diamonds.

How to Buy Diamonds

Many people find buying a diamond, or jewellry containing diamonds, to be an intimidating experience. In part this is because of the cost, since good quality diamonds are not cheap. It is also because buying a diamond seems so hedged around with mystique.

This applies particularly to buying from busy high street jewellers. A person going into a jeweller's shop is often frightened to ask questions, or to insist on making a proper examination of the stone. Either they are afraid of looking foolish, or else of giving the impression that they distrust the jeweller's word about the quality of the diamond. The truth is, if a buyer is going to pay several hundred, or maybe a thousand, pounds, for a diamond, they should, and are entitled to check its clarity and quality for themselves.

Another problem buyers often encounter when buying a diamond is the reluctance of the staff in a jeweller's shop to pull out endless trays, and explaining each diamond in turn. For such a major purchase, a buyer may feel that they want to make two or three visits and think on it in between each visit. To the shop assistant, this makes the buyer a time waster. All these problems can be overcome by buying online, at Internet marketplaces such as eBay .

Finding Diamonds on eBay

When you shop for diamonds on eBay, you can visit the website as often as you like, spend time reading and considering the descriptions, and if you change your mind, or see something you like more, no one is going to worry.

eBay has a very large selection of diamonds for sale, both loose and mounted in jewellery. It is easy search the eBay listings. Simply enter 'loose diamonds' into the search bar on the eBay homepage, and browse through thousands of current listings. You can sort through these easily, by filtering them according to whether they are natural or laboratory diamonds, the carat weight, cut, and clarity. You can also choose to see listings only from those sellers who are located close to you, so that when the time comes that you feel ready to buy, you are close enough to inspect the diamond in person, if you wish.

You can also benefit from the experience of other shoppers, by noting the satisfaction ratings for sellers. Each seller receives feedback ratings from their previous buyers. Those seller's with the best reputations are refereed to as 'Top Sellers'. Because diamonds are a substantial purchase, it is recommended that you only do business with eBay Top-Sellers. You can recognise them by the ribbon icon next to their username in the item listing.


Diamonds are natural crystals that can exhibit considerable variability. This is due to the natural processes involved in their formation. The intense pressure diamonds are subjected to during their formation is sometimes uneven, which can cause irregularities in the structure of the diamond. As a result, inclusions can form that may affect the clarity of the diamond. There are a wide variety of inclusions, but most are very small and invisible except under magnification. The industry standard is to use a 10x magnifier to examine a diamond, and then to classify it according to one of twelve grades.

When shopping for diamonds, it is best to view the stone under magnification, and under different light sources. Although dealing with jewellers can be intimidating for some people, it is worth taking the time to understand the different types of inclusions and other flaws so as to properly assess the clarity of the stone before committing to buying it.

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