Every diamond is unique. How do they exhibit their natural distinctions? As diamonds are formed deep within the earth, under extreme heat and pressure, they often contain unique birthmarks, either internal (inclusions) or external (blemishes).
Diamond clarity is a measure of the number and size of tiny imperfections that inevitably occur in the precious stones. Diamonds with the least and smallest inclusions or blemishes receive the highest clarity grade. Imperfections may be very subtle but their presence can substantially change the value of a diamond. The size, number, colour, location, orientation, and visibility of inclusions and blemishes are all taken into account when evaluating the clarity of a diamond.
Types of inclusions and blemishes can include:
Crystal or Mineral Inclusions: Diamonds commonly have tiny crystals or minerals imbedded within them and can sometimes even be other tiny diamonds. Although the majority of these cannot be viewed without magnification, a significantly sized cluster or mass of crystals does detract a diamond's appearance, lowering its clarity grade and value.
Feathers: These are cracks within the diamond that resemble feathers. Small feathers under the surface do not typically affect a diamond's durability unless they reach the surface of the stone, an area that is more prone to damage.
Needles: Needles are long thin needle-shaped inclusions inside a diamond. They appear as a streak of light inside the stone and can sometimes appear in clusters, affecting the overall clarity and value.
Pinpoints: Pinpoints are tiny light or dark crystals in diamonds that can either appear by themselves or in clusters. Larger clusters of tiny pinpoints can create a hazy area in the diamond, called a cloud, which will affect a diamond's clarity.
Twinning Wisps: This is a result of the crystal entwining into a trail during the stone's original growth.
The GIA grades clarity on an 11-point scale based on the visibility of inclusions under 10x magnification.
FL / IF : No inclusions or blemishes under 10x magnification
VVS1 / VVS2 : Inclusions are difficult to see under 10x magnification
VS1 / VS2 : Inclusions are visible under 10x magnification but can be characterized as minor
SI1 / SI2 : Inclusions are noticeable under 10x magnification
I1 / I2 / I3 : Inclusions are obvious under 10x magnification and could affect transparency and brilliance
FL/IF to VS2 grades are typically referred to by diamond experts as 'eye-clean' and are considered to have no imperfections visible to the naked eye.