Diamond shapes and cuts

• Round brilliant — maximum sparkle, the most expensive and easiest to resell.
• Oval — looks larger per carat; check for a 'bow-tie' dark band across the middle.
• Cushion — soft square, vintage feel; quality varies widely.
• Princess — square, sharp corners need protective claws.
• Emerald and asscher — step cut 'hall of mirrors'; shows inclusions, so buy VS1+.
• Pear and marquise — elongating; watch for bow-tie and protect the points.
• Radiant — brilliant-cut rectangle, very lively.

Old mine and old European cuts (pre-1930s) have a small table, high crown and open culet. Collectors value them; recutting destroys their antique value.

• Ask for the length-to-width ratio on elongated shapes.
• Have any high-value piece checked by an independent valuer or jeweller before paying. JewelleryTrader does not authenticate items.