Diamond Buying Guide

Cut

Cut is how well a diamond's facets interact with light, and it has the greatest effect on sparkle. GIA grades round brilliants from Excellent to Poor. A well-cut diamond returns light through the top as brilliance, fire and scintillation; a poorly cut one leaks light and looks dull.

If you prioritise one C, make it cut. We recommend Excellent or Very Good.

Color

White diamonds are graded on a scale from D (colorless) to Z (light yellow or brown). D–F are colorless, G–J near-colorless, and K and below show visible warmth.

• D–F: icy white, the rarest grades.
• G–H: appear colorless face-up and offer excellent value.
• I–J: a faint warmth that suits yellow and rose gold.

Clarity

Clarity measures inclusions and blemishes, graded under 10× magnification from Flawless (FL) through IF, VVS1–VVS2, VS1–VS2 and SI1–SI2 to Included (I1–I3).

Most buyers look for an eye-clean stone, with no inclusions visible without magnification. VS2 and SI1 diamonds are often eye-clean and considerably better value than VVS. Step cuts such as emerald and asscher show inclusions more readily, so choose a higher clarity for them.

Carat weight

Carat is weight, not size: one carat equals 0.2 grams. Prices rise sharply at popular weights such as 0.50, 0.75 and 1.00 ct, so a 0.90 ct stone can look nearly identical to a 1.00 ct at a noticeably lower price.

Shape also changes how large a diamond looks: ovals, pears and marquises face up larger per carat than rounds.

Certification

Always buy a diamond with an independent grading report. Our stones are graded by GIA or IGI, and each report number can be verified online. Read our certification guide to learn what every line means.

Balancing the 4Cs

• Put cut first: it drives sparkle more than any other factor.
• Choose G–H color and VS2–SI1 clarity for the best look per rupee or dollar.
• Buy just under popular carat weights for the same look at a lower price.
• Pick the shape first; the ideal grades differ by shape.