Clarity is the state of being clear or transparent. Diamond clarity is the presence or absence of characteristics called inclusions in the diamond. The size location and colour of the inclusion defines the grade. These are graded using 10x magnification. Clarity is graded from the highest clarity (flawless or FL) to the lowest clarity (Included 3 or I3).
Diamonds are sold by the carat(shown as ct) which is actually a unit of weight, though most think of a carat in terms of size. today a carat is equal to exactly 0.2grams(about the weight of a paperclip).
Colour really refers to a diamonds lack of colour. Colour generally appears in a diamond as pale yellow. The less colour the higher the colour grade. After the cut colour is the second most important characteristic when selecting a diamond as the human eye detects sparkle first then colour second.
Diamond Cut refers to how well proportioned the diamond is. For example, what percentage of a diamonds diameter is its depth? What are its various angles and how do they interact with one another? These are the essential factors that determine how beautiful your diamond will be.