The low-down on diamond inclusions

Everybody wants the perfect diamond! Unfortunately, it is extremely rare to find a diamond which does not exhibit any imperfections.  Diamond inclusions are characteristics which exist inside a stone. They are most commonly referred to as flaws, because their presence creates a diamond which is not perfect.   Perfect diamonds are available, but at a high price.  Many of us will look at purchasing diamonds with varying types or numbers of both external and internal flaws.

Inclusions are often described to be like fingerprints, unique features which provide a unique signature.  It is important to get familiar with your diamond, both inside and out, to personalise the gem, to help you identify and describe the gem, and to assess the gem’s clarity and value.

Inclusions may be crystals of a foreign material or another diamond crystal, or the prescence of structural imperfections such as tiny cracks that appear cloudy or white. The size, number, colour, relative location, orientation, and visibility of inclusions can all affect the relative clarity of a diamond. A clarity grade is assigned based on the overall appearance of the stone under 10x magnification.

Some diamond inclusions can make a stone prone to shattering or vulnerable to damage.  Some inclusions impinge on the clarity of a diamond, disturbing the stone’s brilliance because they can interfere with light as it travels through it.

There are few perfect diamonds, and the ones that are perfect are quite expensive, so the diamonds we buy all have varying amounts of internal and external flaws. Most jewellers tell us not to worry about diamond inclusions if they do not affect the stone's strength or seriously impact its appearance.

Different forms of diamond inclusions

Crystals or Mineral Inclusions: Diamonds can regularly have miniscule crystals or minerals imbedded within them like any stone would, and these can even be other tiny diamonds. Included and undigested gemstones are more often than not fragments of garnet, diopside, spinel, olivine, calcite, iron oxides, silica – or occasionally diamond itself. The majority of these cannot be viewed prior to magnification.  However, a significantly sized mass or cluster of crystals does detract from a diamond's appearance and therefore lowers its clarity grade, and its value.

In fortunate cases, a small crystal can add special characteristic to a diamond. For example, a diamond with a small garnet imbedded in the centre of it would provide an interesting and personal choice for someone.  Some people like to choose diamonds which contain a fragment of their birthstone (e.g. garnet) or favourite crystal.

Internal Graining: This refers to irregular crystal growth which can cause internal distortions, waviness, or haze within the stone.

Pinpoints: Pinpoints are tiny light or dark crystals present within diamonds that often appear by themselves or in clusters. More significant clusters of minute pinpoints can generate a hazy area which usually appears white in the diamond.  This hazy area is referred to as a cloud and it affects the clarity of any diamond. Clouds are defined therefore as a dense grouping of tiny pinpoints that create a cloudy zone which may not resolve as individual pinpoints at 10X Magnification.

Needles: A needle is a long thin needle-shaped inclusion inside a diamond. They appear as a streak of light inside the diamond and often some diamonds also have cluster of needles together.

Laser Lines: Laser lines are not a natural diamond inclusion as they refer to the internal pathway cause by laser-drilling carried out to remove larger inclusions – but only those where the pathway does not breach the surface of the newly cut diamond.   These trails are vapour-like, left behind when lasers are used to remove dark inclusions from the stone. The machine-made trails appear as small strands of thread and usually begin at the diamond's surface and stretch inwards, disappearing at the point where the natural inclusion was removed.

Feathers: Feathers are cracks within the stone that resemble feathers. The durability of a diamond is usually only affected if feathers reach the surface on the top of the stone, which is more susceptible to accidental pressure or damage.  Small feathers under the surface do not normally create problems.  Cleavage planes or internal stress fractures often have the appearance of feathers and they are also commonly found surrounding included crystals.

Cleavage: Diamond cleavage is a straight crack within the diamond, with no feathering. If hit at the right angle or pressure, a cleavage has the potential to split the diamond divisionally along its length.  Tinier cracks that remain invisible when a diamond is viewed in a face-up or table-up position hardly ever affect the clarity ratings of a stone.

Girdle Fringes or Bearding: Girdle fringes, or bearding, refer to hair-like lines or strands that can occur around the girdle area during the cutting process of a diamond. Minimal fringing is not frequently an issue, and extensive bearding is sometimes polished away or removed by re-cutting or polishing the diamond.

Grain Lines, Growth Lines: Grain lines emerge from irregular crystallization that occurs when a diamond is formed.  Unless grain lines present in big masses, colourless grain lines do not significantly affect diamond clarity.  Prominent white or coloured grain lines can however decrease a diamond's clarity grade.

Carbon spots: Tiny black spots occasionally appear in a diamond, caused by undigested carbon inclusions or natts. Black material found within internal fracture planes can also be crystallographic inclusions of graphite, ferropericlase, pyrrhotite and pentlandite.

Grain Centre: This refers to any concentrated area of crystal growth that can appear light or dark.

Growth Tubes: These are imperfections which were formed during crystal growth, when a tube is generated by a formerly liquid filled cavity.

Twinning Wisps: These wisps are inclusions and defects which are the result of crystal-twining during the original crystal growth and these can also be accompanied by graining and strain.

Knots: An inclusion which is a crystal that appears on the surface of the diamond. This crystal appears as a knot and diamonds having a knot inclusion are commonly rejected as the inclusion is often visible to the naked eye and thus degrades the beauty of the diamond.

The clarity of the diamond you buy is an important criterion that you cannot ignore when you plan to exchange high prices for your dream purchase; you can not compromise on the quality. That is why being aware and knowledgeable about inclusions will help you pick a stone which is acceptable and perfect for you! Always shop for diamonds at a retailer you trust and find someone who can answer your questions about the diamonds you are considering, remembering to ask about characteristics of each diamond under magnification.  Include inclusions in your discussions, and you cannot go wrong!