Carat is weight, not size. How carat relates to face-up millimetres by shape, why prices jump at 0.50, 1.00 and 1.50 ct, and how to buy just below them.
Everything to know before you buy an engagement ring, in eight clear steps: budget, stone type, shape, the 4Cs, setting, metal, paperwork, sizing and care.
What the D-to-Z diamond colour scale means, which grade looks white in your shape and metal, and how to compare grades without overpaying.