Diamonds in their perfect form are a rare phenomenon. Most of the diamonds that are naturally formed are born with some inclusions or imperfection. Another name for inclusions is ‘flaws’ and they are classified into external flaws and internal flaws. When a diamond is graded, the gemologist takes into consideration the size of the inclusion, the number of inclusions, the nature of the inclusion, the position of the inclusion etc,. Apart from the fact that these characteristics impact the clarity and value of the diamond, they also render a unique identity to the diamond. The inclusions exist in various forms and listed below are some of the most common types of inclusions:

  • Cavity: It is a large or deep opening on the surface of the diamond. They usually happen during the polishing process where the internal inclusions may accidentally fall out or may even happen if a cutter removes the crystal inclusion that are close to the surface of the diamond.
  • Cloud: Three or more pinpoint inclusions when present at close proximity create a hazy or cloudy like inclusions in the diamond. Small clouds are not visible to the naked eye, but the presence of a large number of pinpoints spanning a large area will surely affect the clarity of the diamond.
  • Feather: As the name implies, these inclusions are cracks that take the form of feathers. If the feather spans a major length of the diamond, there is a possibility that the diamond might crack or break further thus reducing the durability of the diamond altogether.
  • Needle: The diamond crystals can also be present in the shape of long and thin needles. They are not usually visible to the naked eye, but the existence of noticeable color may make its presence apparent.
  • Bearding: These are inclusions that exist around the diamond’s girdle and usually occurs after the diamond is bruted or cut. They are also known as girdle fencing or dig marks and usually resembles a strand of hair. They do not pose much of a problem though extensive bearding may reduce the luster of the diamond.
  • Pinpoint: They are tiny white or black crystals that exist inside the diamond. They look like a small point of light and do not normally affect the clarity of the diamond and are also not visible to the naked eye. They are the most common types of flaws present in diamonds.
  • Cleavage: They are cracks that usually look like straight lines and parallel to a diamond’s crystallographic planes. Cleavage is a result of hard blow or deep internal strain and they make the stone susceptible to split.
  • Crystals: Crystals are basically mineral inclusions. The minerals may be of different types and they can also be colorless. Colored crystals become apparent to the naked eye and hence they are usually avoided. There are also crystals that resemble a diamond and this only enhances the appearance of the stone.
  • Graining: These are inclusions that appear in the form of lines and are known as grain lines. They are the result of improper crystallization of the diamond during its formation or due to its improper polishing.
  • Twinning Wisps: During the period of its formation, a diamond may develop certain growth defects and as a result may stop growing. When the growth restarts again, twinning wisps are formed in several directions.


Posted by Roy Izakov.
© Copyright 2016 Motek Diamonds by IDC.