Another important consideration is the cut of the diamond, though this has more to do with personal preference than anything else. Traditionally, the most common and popular cut is the round, or brilliant, cut.
Round cut © thediamondstore.co.uk
Princess or square cut stones are also becoming increasingly popular, while marquise and pear cuts remain relatively unusual.
The different cuts correlate differently to carats and size. A one carat pear shaped diamond, for instance, will be a different size than a one carat round shaped diamond.
In addition to the famous four, there is a fifth C that is important to consider: certification. A certificate will confirm that the diamond you’re being sold is what the retailer says it is. It’s generally a good rule of thumb to go with a diamond that’s been independently certified, Ingram says, particularly when you start getting into more expensive stones.