3 Carat · Round
3 carat round lab-grown diamond.
Approximately 9.4 mm in diameter, cut to the Montare floor — VVS, D/E, Triple Excellent, IGI certified.
A 3 carat round lab-grown diamond is one of the most-searched stones we make — and one of the clearest demonstrations of what lab-grown supply changed. Here is what the size actually looks like, how the round cut wears, and what it costs when you buy it from the workshop instead of a retail floor.
What a 3 carat round looks like
Carat measures weight, not width. At three carats a round reads as a true centre stone on an average ring finger — the point where presence and proportion meet.
The round character
The benchmark. Fifty-eight facets engineered to return the maximum light back to the eye, and the most forgiving shape there is — a Triple Excellent round looks extraordinary on every hand. If you are uncertain, choose round.
The Montare standard
Every 3 carat round we set holds the same floor: VVS1–VVS2 clarity, D or E colour, Triple Excellent cut, IGI certified. Not a premium upgrade — the baseline. Cut is the variable that decides how a diamond actually looks, which is why we will not drop below Triple Excellent for any saving. Read why Triple Excellent matters.
Why it costs less than you would expect
A 3 carat lab-grown round is physically and chemically identical to a mined stone of the same grade — and at the same specification it costs dramatically less, with none of the extraction. Working factory-direct from our Toronto workshop removes the retail markup on top of that. See where the retail markup actually goes.
Keep exploring
- Round engagement ring settings →
- How much a 3-carat lab-grown diamond costs →
- Lab-grown engagement rings in Canada →
Common questions
How big is a 3 carat round lab-grown diamond?
A 3 carat round diamond measures roughly 9.4 mm in diameter face-up. Carat is a measure of weight, not size, so the visible footprint depends on shape — elongated cuts look larger on the hand than their carat weight suggests.
How much is a 3 carat lab-grown round diamond?
Far less than its mined equivalent and far less than retail. An identically graded stone that runs $11,000 and up in a jewellery store costs a fraction of that factory-direct from Montare. Model your exact configuration on our pricing tool.
Is a 3 carat round diamond too big?
Three carats is the Montare floor because below it a centre stone starts to read tentative on most hands. A 3 carat round is a confident size — present without tipping into costume.
Are Montare's 3 carat round diamonds certified?
Yes — every stone is IGI certified at VVS1–VVS2 clarity, D/E colour and Triple Excellent cut, with the report number inscribed on the diamond. We will not set below that floor.