3.5 Carat Lab Grown Diamond Engagement Rings

Browse examples, or shop diamonds & settings.

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The High Jewelry Standard for Lab Grown Diamonds.

At Ada Diamonds, we specialize in curating the highest-quality lab diamonds set in made-to-order engagement rings. Each piece is produced start to finish under one roof in our NYC flagship.

No matter what you're shopping for, our team of experts is here to support you in bringing your vision to life.

Browse the gallery below to see 3.5 carat rings we've created for past Ada clients.

What to Know

3.5 carats is a size for people who know what they want. It's substantial, distinctive, and a size where the quality of the stone really matters.

No matter what size diamond you're considering, curation matters. You should never choose a diamond based on a grading report alone. While two diamonds may share identical 4Cs, they can look very different in person. Every diamond at Ada is hand-selected in person by our expert team. We curate only the rare few lab grown diamonds that meet our standards for cut precision, light performance, and beauty in real life.

Why Ada Diamonds

We know that a purchase this important deserves an exceptional experience. Whether you purchase online, or enjoy complimentary design support with a Diamond Concierge, each piece is made to order and crafted in house from start to finish. Our master jewelers create each setting one at a time, built specifically for its stone. Nothing is mass-produced. Every detail is considered, refined, and made to last for a lifetime.

Browse 3.5ct Engagement Rings

3.5ct round six prong lab diamond solitaire two tone
3.5ct round six prong solitaire two tone on model
3.5ct radiant cut lab diamond three sided pave band platinum
3.5ct radiant cut lab diamond pave ring platinum on model
3.5ct cushion lab diamond solitaire two tone yellow gold and platinum
3.5ct cushion cut lab diamond ring two tone on model
3.5ct asscher and trapezoid three stone lab diamond ring platinum
3.5ct asscher and trapezoid three stone platinum on model
3.5ct pear lab diamond solitaire yellow gold
3.5ct pear solitaire lab diamond yellow gold on model
3.5ct round cathedral pave lab diamond ring platinum
3.5ct round cathedral pave lab diamond ring platinum on model
3.5ct pear lab diamond pave band ring platinum
3.5ct pear cathedral pave ring platinum on model
3.5ct oval and trapezoid three stone lab diamond ring platinum on model
3.5ct oval and trapezoid three stone lab diamond ring platinum
3.5ct oval petite four prong solitaire lab diamond platinum macro
3.5ct oval lab diamond solitaire yellow gold on model
3.5ct emerald and baguette three stone lab diamond ring platinum
3.5ct cushion petite four prong solitaire platinum macro
3.5ct cushion cut lab diamond solitaire platinum on model
3.5ct emerald and baguette three stone lab diamond ring platinum on model
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3.00ct F VVS2 Excellent Round

RoundRound
3.00FVVS2$5,475
3.00ct F VVS2 Excellent Round

3.00ct F VVS2 Excellent Round

$5,475

See Details
ShapeRound
Carat3 CT
CutExcellent
ColorF
ClarityVVS2
Measurements9.19 x 9.15 x 5.74
LabGIA
L/W Ratio1.00

3.01ct D VVS2 Pear

PearPear
3.01DVVS2$6,775
3.01ct D VVS2 Pear

3.01ct D VVS2 Pear

$6,775

See Details
ShapePear
Carat3.01 CT
ColorD
ClarityVVS2
Measurements12.84 x 7.99 x 5.05
LabIGI
L/W Ratio1.61

3.02ct D VVS1 Cushion

Elong.Cushion
3.02DVVS1$7,250
3.02ct D VVS1 Cushion

3.02ct D VVS1 Cushion

$7,250

See Details
ShapeElongated Cushion
Carat3.02 CT
ColorD
ClarityVVS1
Measurements9.50 x 7.69 x 5.41
LabGIA
L/W Ratio1.24

3.03ct D VS1 Emerald

EmeraldEmerald
3.03DVS1$5,900
3.03ct D VS1 Emerald

3.03ct D VS1 Emerald

$5,900

See Details
ShapeEmerald
Carat3.03 CT
ColorD
ClarityVS1
Measurements10.40 x 6.74 x 4.21
LabGIA
L/W Ratio1.54

3.05ct E VVS2 Marquise

MarquiseMarquise
3.05EVVS2$6,325
3.05ct E VVS2 Marquise

3.05ct E VVS2 Marquise

$6,325

See Details
ShapeMarquise
Carat3.05 CT
ColorE
ClarityVVS2
Measurements14.43 x 7.79 x 4.84
LabIGI
L/W Ratio1.85

3.07ct D VS1 Marquise

MarquiseMarquise
3.07DVS1$6,150
3.07ct D VS1 Marquise

3.07ct D VS1 Marquise

$6,150

See Details
ShapeMarquise
Carat3.07 CT
ColorD
ClarityVS1
Measurements14.76 x 7.71 x 4.83
LabIGI
L/W Ratio1.91

3.08ct D VVS2 Emerald

EmeraldEmerald
3.08DVVS2$6,775
3.08ct D VVS2 Emerald

3.08ct D VVS2 Emerald

$6,775

See Details
ShapeEmerald
Carat3.08 CT
ColorD
ClarityVVS2
Measurements10.17 x 6.75 x 4.56
LabGIA
L/W Ratio1.51

3.08ct D VVS2 Oval

OvalOval
3.08DVVS2$6,775
3.08ct D VVS2 Oval

3.08ct D VVS2 Oval

$6,775

See Details
ShapeOval
Carat3.08 CT
ColorD
ClarityVVS2
Measurements11.29 x 8.29 x 5.17
LabIGI
L/W Ratio1.36

3.5ct Lab Diamond FAQs

  • How do I choose a carat weight for my engagement ring?

  • What should I look for when choosing a lab diamond?

  • How does Ada select lab diamonds?

  • Can I design a custom ring?

  • Does Ada sell loose diamonds?

Explore Our Guides

View More
Color

Color

Diamond color measures the subtle tint present in a diamond. Learn how the D–Z color scale works, what color grades look white to the eye, and how Ada Diamonds evaluates lab diamonds for brightness and undesirable color undertones.

Diamond Education

Clarity

Clarity

Clarity is a measurement of how many or how large of blemishes or inclusions are present in the diamond. The lower the clarity of a diamond, the more imperfections in the diamond. Lab diamonds vary in clarity, just like mined diamonds.

Diamond Education

Carat

Carat

Carat weight measures how much a diamond weighs, not how large it appears. Learn how carat weight influences a diamond’s size, rarity, and price, and how Ada Diamonds helps clients find the right balance of beauty, proportions, and value.

Diamond Education

Platinum vs White Gold: Which Metal is Best For My Ring?

Platinum vs White Gold: Which Metal is Best For My Ring?

White gold or platinum? Let’s break it down. Both are timeless choices for engagement rings, offering that clean, classic look we all love. Not sure which metal is right for you? Our design experts are here to help. 

Diamond Education

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