Cut is not the same as shape. It describes how precisely a diamond’s facets are proportioned to catch and return light. A well-cut diamond is full of fire and sparkle; a poorly cut one looks dull and lifeless, even with excellent colour and clarity.

Diamond colour is graded from D (completely colourless) to Z (light yellow). The less colour a diamond has, the rarer and brighter it appears in white-metal settings.

Clarity measures tiny natural marks inside a diamond. Most are invisible to the naked eye. The practical goal is an eye-clean diamond.

Carat is a measure of weight, not size. Two diamonds of equal carat can look different sizes depending on how they are cut.