3 carat round lab-grown diamonds
Round brilliants from 3.00 to 3.49 carats, for statement solitaires and larger pieces.
A 3 carat round is about 9.1 mm across. That is a centre stone customers notice across a room, and at this size the cut is doing most of the work. Proportions that would pass unnoticed in a smaller stone, such as a slightly deep pavilion or a thick girdle, show up as a darker centre or a smaller spread than the weight suggests.
Read the full report before you shortlist. Look at table and depth percentages, girdle thickness and the measurements line, and compare stones of similar weight against each other rather than against a grade alone. The 1 mm preview grid on this page helps you see outline and spread before you request.
Large rounds are usually bought for one client, so most requests at this weight are for a single stone in a specific colour and clarity. If you are quoting a specific piece, send the specification you need with your shortlist and we will reply with pricing and availability. Every certified stone carries an IGI or GIA report and a laser inscription. We supply the trade only, from our Los Angeles office.
How big is a 3 carat round lab-grown diamond?
About 9.1 mm across for a well-cut stone. Check the report measurements, since depth changes face-up size.
Which lab grades your 3 carat stones?
Certified stones are graded by IGI or GIA. The certificate filter lets you show one lab or both.