What a 3 carat diamond looks like
A 3 carat round is 9.3 to 9.4mm across. Natural stones this big are scarce, and the price per carat shows it: $17,052 in October 2026, against $3,419 at 1 carat.
Dollar gaps between retailers get large at this size. For the same G / VS1 natural round, Rare Carat's October median was $45,865 and Blue Nile's was $56,334. About $10,500 apart. The retailer comparison above has this month's spread.
What to check at 3 carats
A 3 carat stone shows inclusions that a 1 carat stone would hide. Faint body color is easier to pick up too, especially in ovals and cushions, where it gathers at the ends. A grade on a certificate covers a range of stones, so before you pay, ask for photos or video of the exact one you're buying.
October's lab-grown 3 carat round median was $1,819, about $49,000 under natural. If you go that way, read HPHT vs CVD and GIA vs IGI for lab-grown first.