The 4Cs of Diamonds - cut, colour, clarity, and carat weight - the most important characteristics to understand when making a diamond purchase.

Diamond Cut
The diamond cut is the most important element to consider when buying a diamond. The cut is the biggest factor in creating sparkle and fire, and without a high cut grade even a diamond of high quality can appear dull and lifeless. A diamond cut poorly and too deep can face-up smaller than it actually is. Use our buying tips, diamond cut grading scale and comparison chart, and expert tips to help you choose the best diamond cut for your budget.

Diamond Anatomy
The graphic below explains the major parts of a diamond. When considering diamond anatomy, the three most important components are diameter, table, and depth. This is because the ratio of the table to the diameter, and the depth to diameter, figure prominently into determining a diamond's cut grade.

While understanding a diamond's anatomy can be helpful, it should not supersede the importance of or be confused with cut grade. The various parts of a diamond and how well they are cut are included as part of a diamond's cut grade.

Diameter: The width of the diamond as measured through the girdle.

Table: The largest facet of a gemstone.

Crown: The top portion of a diamond extending from the girdle to the table.

Girdle: The intersection of the crown and pavilion which defines the perimeter of the diamond. While generally a minor consideration, we recommends avoiding girdles graded either extremely thin, which makes diamonds more susceptible to chipping, or extremely thick, which puts too much weight in the middle of the diamond, causing it to look smaller than diamonds of similar weight.

Pavilion: The bottom portion of a diamond, extending from the girdle to the culet.

Culet: The facet at the tip of a diamond. The preferred culet is not visible with the unaided eye (graded "none" or "small").

Depth: The height of a diamond measured from the culet to the table.

Diamond Colour

After diamond cut, diamond colour is the second most important characteristic to consider when choosing a diamond. The highest quality diamonds are colourless, while those of lower quality have noticeable colour, which manifests as pale yellow in diamonds.

The Gemological Institute of America (GIA) grades diamond colour on a scale of D (colourless) to Z (light yellow or brown). D-Z diamonds are also known as white diamonds, even though most diamonds, including H colour diamonds and G colour diamonds, have varying amounts of colour.

If you're looking to buy fine diamond jewellery such as an engagement ring, it's important to understand how diamond colour affects price. Below are a few buying tips and things to know about diamond colour.

• For the best balance between quality and value, choose G-I diamond colour grades in the Near Colourless category. To the naked eye, the difference between diamonds of one colour grade (G-H or I-J) is practically indistinguishable, and the savings can be significant. The faint warmth of a J and K colour diamonds can be difficult to discern to the naked eye, especially when set in yellow gold. When side by side with a colourless diamond, or in a white gold or platinum setting, however, the warmth of J or K colours is more noticeable.
• In general, to avoid a pale yellow colour, choose a diamond grade H or higher. For the purist, look for a D to F grade colourless diamond, which will have no discernible colour under magnification.
• Pairing diamonds with similar toned metals can neutralise colour in the diamond. Consider setting higher colour grade diamonds like Near Colourless (G-J) or Faint Colour (K) diamonds in yellow gold and Colourless diamonds (D-F) in white gold or platinum. A gold setting may show through a colourless diamond.
•  Some diamond shapes may show or mask colour to varying degrees. For example, brilliant-cut shapes such as round and princess reflect more light, which means more colour is masked. Step-cut diamonds (emerald and Asscher cuts) may show more colour because they are cut with fewer facets, resulting in bigger "windows" through which to see the colour. 
• Colour is easier to see in larger diamonds. If you want a diamond above 1 carat, choose a G or H coloured diamond. I-K colour diamonds are best when just under a carat.