The first three C’s are fairly straight forward, referring to carat weight, colour and clarity, indicating the size of inclusions in a diamond.  However, cut is a more nuanced characteristic, referring to the quality of proportions, symmetry and polish of a diamond.  It ultimately has three primary effects on appearance. 

Cut is vital to the amount of brilliance emitted when the light enters a stone and reflects back out. In simple terms: When a diamond is cut too shallow the light entering the stone will reflect back out through the side of the stone. When a diamond is cut too deep the light entering the stone will reflect back out through the bottom of the stone. 

1. Carat weight
This is the standard mass unit for diamonds and other gemstones. The word "carat" comes from the old Greek word for the seed of a carob tree, "kerátion'. It is important to note there is a difference between Carat, which denotes the weight of diamonds and gemstones, and gold Karat – the purity of gold alloys.
The purest white diamonds are colourless with no hue and, consequently, have a higher value. However, diamonds can range in colour from white to yellow, brown and fancy colours. A standard diamond's colour is measured on a scale identifying the degree of colourlessness by comparing a stone under controlled lighting and precise viewing conditions to masterstones.
The clarity grade assesses a diamond for the presence and severity of flaws. No diamond is 100% perfect. With enough magnification you can find a flaw in the cleanest stone. Most flaws are naturally created when the diamond formed in the subterranean pressure of the Lithosphere. Other flaws can originate while cutting and polishing the stone.
4. Cut
Cut identifies how closely the diamond has been cut and polished to ideal proportions. A diamond's cut is not only about its shape, but how effectively the stone can return light back to the viewer's eye. A well-cut diamond will be seen as brilliant and sparkling. A poorly cut diamond may have the highest colour and perfect clarity yet it will look lifeless.


A well cut diamond reflects light back out through the top of the stone, creating the brilliant appearance we all fall in love with. These factors are all to be considered when you’re browsing through diamonds for sale.


It affects fire, the dispersion of light into flashes of colour and it gives a diamond its scintillation, the sparkle it gives off when moved, but cut can also add a lot more value and is an important factor contributing to the value of a diamond.

When it comes to colour, fancy shape diamonds show their colour easier than a round brilliant cut diamond. Did you know that diamonds are actually graded in colour upside down? There is a loose term “face up” also used by diamond dealers. This translates that the stone appears brighter in colour from the top than the actual bottom grading. This makes it vital for a prospective buyer to view the stone in person.

A very interesting factor that is often mentioned on a diamond certificate is fluorescence. Fluorescence does by no means affect the diamonds’ integrity. Diamonds with fluorescence can actually cost 10% to 20% less. Besides the cost savings, fluorescence can typically improve the appearance of a diamond’s colour, sometimes by up to two shades in colour. This is applicable in grades H through K.  

All the cuts in the brilliant diamond family: round brilliant, princess cut, oval cut, trilliant cut, pear cut, marquise cut, radiant cut, heart cut and cushion cut have brilliance that enhances the stone. The family of step cut stones: emerald cut, asscher cut and baguette cut, rely on flashes rather than brilliance for their magnificent appearance.