No diamond should be purchased without independent verification. A diamond certificate (or grading report) is the blueprint of the stone.
Once a budget is set, the buyer must determine which visual aspect of the diamond matters most to them. Because perfect diamonds are exceedingly rare and expensive, buying a diamond is an exercise in compromise. Most buyers must choose between maximising size (carat) or maximising sparkle and purity (cut and clarity). The 4 Cs: The Universal Grading Standard how to buy a diamond
Clarity assesses the presence of internal characteristics called "inclusions" and external characteristics called "blemishes." The scale ranges from Flawless (FL) to Included (I). Flawless/Internally Flawless. VVS1/VVS2: Very, Very Slightly Included. VS1/VS2: Very Slightly Included. SI1/SI2: Slightly Included. Because perfect diamonds are exceedingly rare and expensive,
Furthermore, the colour of the metal setting should influence your diamond choice. If you choose a yellow or rose gold band, you can buy a lower colour grade diamond (like a J or K), as the warm metal will mask the slight yellow tint of the diamond. Verification and Ethics Flawless/Internally Flawless
A well-cut diamond reflects light internally from one facet to another and disperses it through the top.