4C’s of Diamond Quality

Each and every Diamond, whether created billions of year ago or more recently lab-grown has unique characteristics.   So how can you understand the difference between them and which ones are ‘better than others’.   It wasn’t until the mid 20th century that GIA created the first, and now globally accepted standard for describing diamonds: Color, Clarity, Cut and Carat Weight. Today, the 4Cs of Diamond Quality is the universal method for assessing the quality of any diamond, anywhere in the world. This benefited the consumer as there was now a method to compare diamonds.


Of the four-measure it is the cut that has the greatest ability to transmit light and sparkle so intensely.   To turn the diamond into a beautiful gem, the diamond is cut into a specific shape with precise facets, tiny polished faces. Popular diamond cuts include Round, Princess, Marquise, Pear, and Emerald.  A well-cut diamond will have an amazing brilliance and fire. This is caused by white light reflecting off the diamond’s surfaces and the mirrored depths of the pavilion. The key to desirable fire and brilliance is proportion. An Excellent Cut Diamond will carry light down into the stone and shoot it back out the top. This is what creates the “Brilliance”. Diamonds International prides itself on the number of Excellent Cut Diamonds we stock. Light striking a shallow cut diamond will fall out the other side and not reflect back to the top.

Diamond cuts are rated on a scale of Excellent, Very Good, Good, Fair and Poor. The score is based on the width of the table, height of the crown and the depth of the pavilion in each diamond.

Diamond Cut


The next most important measure for diamond quality is their colour.   Rated most highly is the colourless diamond, and the colour scale moves from colourless through to less desirable yellow.  While many diamonds may, at first glance appear colourless, or white, they can actually have subtle yellow or brown tones, caused by natural forces during the formation of the diamond in the earth.

Colourless diamonds are considered to be the rarest and most valuable of all. Because subtle colour variations dramatically affect the value of a diamond, a colour grading scale is used to categorize the shading differences from one diamond to the next.

Colour is rated from the colourless D rating down to yellow-tinted K colour

The rarest and highest quality with a pure icy look.

  • D-F Colour Diamonds

Near-colourless diamonds: No discernible colour; great value for the quality.

  • G-H Colour Diamonds
  • I-J Colour Diamonds

Faint colour diamonds: Budget-friendly pick; pairs beautifully with yellow gold.

  • K Colour DiamondsDiamond Colours


Carat is the easiest measure for consumers to understand as this is a rating of weight so the large the value, the bigger the diamond. A metric “carat” is defined as 200 milligrams. Each carat is subdivided into 100 ‘points.’ This allows very precise measurements to the hundredth decimal place. A jeweller may describe the weight of a diamond below one carat by its ‘points’ alone. For instance, the jeweller may refer to a diamond that weighs 0.25 carats as a ‘twenty-five pointer.’ Diamond weights greater than one carat are expressed in carats and decimals. A 1.08 carat stone would be described as ‘one point oh eight carats.’

All else being equal, diamond price increases with diamond carat weight because larger diamonds are rarer and more desirable. However, two diamonds of equal carat weight can have very different values (and prices) depending on three other factors of the diamond quality 4CsColorClarity, and Cut.

diamond Carat


The measure of clarity requires a level of expertise to assess the blemishes and inclusions in a diamond.   Diamond clarity is the assessment of small imperfections on the surface and within the stone. Surface flaws are called blemishes, while internal defects are known as inclusions. In most cases, a diamond’s beauty is not affected by these in any way since most inclusions can’t be seen with the naked eye. When referring to inclusions, gemmologists often use the term “internal characteristics” instead of flaws. Internal characteristics are what give a natural diamond its character. It’s also important to note that diamonds with the fewest and smallest inclusions receive the highest clarity grades—and higher price tags to reflect that.

The rating system for clarity includes :

I1, I2, I3 Included Diamonds

  • I clarity diamonds have obvious inclusions that are likely to be visible and impact beauty

SI1, SI2 Slightly Included (SI) Diamonds

  • Inclusions are noticeable at 10x magnification
  • If eye clean, SI diamonds are often the best value
  • SI2 inclusions may be detectable to a keen unaided eye, especially when viewed from the side

VS1, VS2 Very Slightly Included (VS) Diamonds

  • Minor inclusions ranging from difficult (VS1) to somewhat easy (VS2) to see at 10x magnification
  • Great value; the most popular diamond clarity

VVS1, VVS2 Very, Very Slightly Included (VVS) Diamonds

  • VVS diamonds have minuscule inclusions that are difficult even for trained eyes to see under 10x magnification
  • VVS clarity is rare and results in an eye clean appearance
  • Characteristics are minuscule and difficult to see under 10x magnification, even to a trained eye

Internally Flawless (IF) Diamonds

  • Some small surface blemishes may be visible under a microscope on IF diamonds
  • IF diamonds have no inclusions within the stone, only surface characteristics set the grade
  • Visually eye clean

Flawless (FL) Diamonds

  • No internal or external characteristics
  • Less than 1% of all diamonds are FL clarity
  • A flawless diamond is incredibly rare because it’s nearly impossible to find a diamond 100% free of inclusions


Diamond Clarity

Remember, all diamonds are unique, not perfect. It does not matter if they were made underground through enormous pressure and heat, or lab-grown, inclusions, and blemishes are inevitable.

That’s why at idem Diamonds we offer all diamond quality types to help you choose what’s right for you.

One Comment

  1. Padmakar Parasharam Babare

    I impress the quality of real diamond. I read the information about diamond.

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