How Much Does a 3-Carat Lab-Grown Diamond Cost?

The honest 2026 answer — and why the same stone costs a fraction of mined.

A 3-carat lab-grown diamond is one of the best values in fine jewellery today. A mined 3-carat round in top colour and clarity can run $50,000 to $100,000+ CAD. A lab-grown diamond of the same size and grade — chemically and optically identical — costs a small fraction of that, which is exactly why a 3-carat ring is now within reach for many couples.

The Montare standard (our floor, not our ceiling): every diamond is lab-grown, D–E colour, VVS1–VVS2 clarity, Triple Excellent cut with ideal table & depth, IGI certified, and 3 carat minimum. Made to order in Toronto.

What actually drives the price

Lab-grown or mined, a diamond’s price comes down to the 4Cs:

  • Carat — bigger stones are rarer to grow well, so price climbs with size (not linearly).
  • Cut — the single biggest driver of how a diamond looks. A Triple Excellent cut returns the most light.
  • Clarity — VVS1–VVS2 means inclusions are invisible to the naked eye.
  • Colour — D–E is the colourless top of the scale.

Most retailers let you drop these grades to hit a price. Montare doesn’t: we hold every stone to the same floor, so the only real variable is size.

Lab-grown vs mined: a 3-carat comparison

3ct round, D/E, VVS, Triple Excellent Indicative price
Mined diamond (stone alone) ~$50,000–$100,000+ CAD
Lab-grown diamond (stone alone) a fraction of the above
Montare ring (stone + fine setting, made to order) see your exact price in the pricing tool

Because lab-grown removes the mining and scarcity premium, your budget goes into the things you actually see — size, cut quality, and the setting.

How Montare prices a 3-carat ring

Every Montare ring is priced transparently: the setting plus a centre diamond held to our standard. You can build your ring and watch the price update live as you choose shape, carat, clarity and metal — no hidden markups, no negotiation. Want a number for your exact design? Our diamond pricing tool shows it instantly, or a specialist will quote it during your consultation.

Is a 3-carat lab-grown diamond worth it?

For most couples, yes. You get genuine 3-carat presence, top-tier cut, colour and clarity, IGI certification, and lifetime free upgrades — for a fraction of what the same stone would cost mined. It’s the clearest case in the category for spending less on origin and more on the ring itself.

Frequently asked questions

Is a 3-carat lab-grown diamond cheaper than mined?
Yes — dramatically. A 3-carat lab-grown diamond of equal quality typically costs a small fraction of a mined equivalent, because the price reflects craftsmanship and the stone itself rather than mining and scarcity markups.
Are lab-grown diamonds real diamonds?
Yes. A lab-grown diamond is chemically, physically and optically identical to a mined diamond — same carbon crystal, same hardness (10 on the Mohs scale), same fire. It is graded and certified the same way.
Why is 3 carats the Montare minimum?
Three carats is our floor, not a premium tier. We believe presence on the hand should not be a compromise, so every Montare engagement ring starts at 3 carats and is held to a VVS, D/E, Triple Excellent standard.
How do I see the exact price for my ring?
Use our live pricing tool or ring builder to configure shape, carat, clarity and metal and see your exact price instantly, or book a consultation for a tailored quote.

Related guides

Design yours, or just ask us.

Build your ring in our live configurator, or book a complimentary one-on-one consultation with a Montare diamond specialist — no obligation, same-day response.

See your price →Book a consultation →

3-carat size & price by diamond shape

Carat is weight, not width, so the same three carats looks different in each shape. See the approximate dimensions and factory-direct pricing for each: