Home 3 Carat Lab Grown Diamond Rings

3 Carat Lab Grown Diamond Rings

Complete engagement rings with the IGI certified lab grown diamond already set, made to order in our Los Angeles atelier at one price.

Prefer to Build Your Own? →
Eloise Select Halo Round Lab Diamond Engagement Ring in 18K White Gold, on hand, angled | RockHer

The Eloise Select Halo Round Lab Diamond Engagement Ring in 18K White Gold

Select Halo Round · 18K White Gold

From $4,475

Lab Diamond Included
Brenda Select Oval 18K Yellow Gold

The Brenda Select High Hidden Halo Solitaire Oval Lab Diamond Engagement Ring in 18K Yellow Gold

Select High Hidden Halo Solitaire Oval · 18K Yellow Gold

From $3,780

Lab Diamond Included
Bianca Select Halo Cushion Cut Lab Diamond Engagement Ring in Platinum, shown on hand, angled | RockHer

The Bianca Select Halo Cushion Cut Lab Diamond Engagement Ring in Platinum

Select Halo Cushion Cut · Platinum

From $4,595

Lab Diamond Included
Daisy Select Pavé Oval Lab Diamond Engagement Ring in 14K Rose Gold, on hand, angled | RockHer

The Daisy Select Pavé Oval Lab Diamond Engagement Ring in 14K Rose Gold

Select Pavé Oval · 14K Rose Gold

From $4,750

Lab Diamond Included
Crimson Select Halo Oval Lab Diamond Engagement Ring in 18K White Gold, shown on hand, angled | RockHer

The Crimson Select Halo Oval Lab Diamond Engagement Ring in 18K White Gold

Select Halo Oval · 18K White Gold

From $4,620

Lab Diamond Included
Floria Select Solitaire Oval Lab Diamond Engagement Ring in 18K Yellow Gold, on hand, angled | RockHer

The Floria Select Solitaire Oval Lab Diamond Engagement Ring in 18K Yellow Gold

Select Solitaire Oval · 18K Yellow Gold

From $2,970

Lab Diamond Included
Allegra Select Halo Round Lab Diamond Engagement Ring in 14K Rose Gold, on hand, angled | RockHer

The Allegra Select Halo Round Lab Diamond Engagement Ring in 14K Rose Gold

Select Halo Round · 14K Rose Gold

From $3,930

Lab Diamond Included
The Dolly radiant engagement ring setting in 14K Rose Gold | RockHer

The Dolly Select Double Hidden Halo Solitaire Radiant Cut Lab Diamond Engagement Ring in 14K Rose Gold

Select Double Hidden Halo Solitaire Radiant Cut · 14K Rose Gold

From $4,020

Lab Diamond Included
Presley Select Pavé Round Lab Diamond Engagement Ring in 18K White Gold, on hand, angled | RockHer

The Presley Select Pavé Round Lab Diamond Engagement Ring in 18K White Gold

Select Pavé Round · 18K White Gold

From $4,930

Lab Diamond Included
Carnie Select Halo Princess Cut Lab Diamond Engagement Ring in 18K Yellow Gold, front view | RockHer

The Carnie Select Halo Princess Cut Lab Diamond Engagement Ring in 18K Yellow Gold

Select Halo Princess Cut · 18K Yellow Gold

From $3,990

Lab Diamond Included
Kate Select Halo Oval Lab Diamond Engagement Ring in Platinum, shown on hand, angled | RockHer

The Kate Select Halo Oval Lab Diamond Engagement Ring in Platinum

Select Halo Oval · Platinum

From $5,465

Lab Diamond Included
Celine Select Halo Oval Lab Diamond Engagement Ring in 14K Rose Gold, on hand, angled | RockHer

The Celine Select Halo Oval Lab Diamond Engagement Ring in 14K Rose Gold

Select Halo Oval · 14K Rose Gold

From $5,365

Lab Diamond Included
Cecilia Select Double Halo Round Lab Diamond Engagement Ring in 18K White Gold, on hand, angled | RockHer

The Cecilia Select Double Halo Round Lab Diamond Engagement Ring in 18K White Gold

Select Double Halo Round · 18K White Gold

From $6,985

Lab Diamond Included
Calliope Select Halo Oval Lab Diamond Engagement Ring in 18K Yellow Gold, shown on hand, angled | RockHer

The Calliope Select Halo Oval Lab Diamond Engagement Ring in 18K Yellow Gold

Select Halo Oval · 18K Yellow Gold

From $5,045

Lab Diamond Included
Selena Select Bezel Solitaire Round Lab Diamond Engagement Ring in Platinum, front view | RockHer

The Selena Select Bezel Solitaire Round Lab Diamond Engagement Ring in Platinum

Select Bezel Solitaire Round · Platinum

From $3,015

Lab Diamond Included
Carole Select Pavé Round Lab Diamond Engagement Ring in 14K Rose Gold, on hand, front | RockHer

The Carole Select Pavé Round Lab Diamond Engagement Ring in 14K Rose Gold

Select Pavé Round · 14K Rose Gold

From $4,180

Lab Diamond Included
Charlie Select Solitaire Oval Lab Diamond Engagement Ring in 18K Yellow Gold, on hand, angled | RockHer

The Charlie Select Solitaire Oval Lab Diamond Engagement Ring in 18K Yellow Gold

Select Solitaire Oval · 18K Yellow Gold

From $3,945

Lab Diamond Included
The Miley emerald engagement ring setting in 18K Yellow Gold | RockHer

The Miley Select Solitaire Emerald Cut Lab Diamond Engagement Ring in 18K Yellow Gold

Select Solitaire Emerald Cut · 18K Yellow Gold

From $2,520

Lab Diamond Included
Peggy Select Bezel Accent Solitaire Oval Lab Diamond Engagement Ring in Platinum, side view | RockHer

The Peggy Select Bezel Accent Solitaire Oval Lab Diamond Engagement Ring in Platinum

Select Bezel Accent Solitaire Oval · Platinum

From $3,535

Lab Diamond Included
Brandi Select Solitaire Round Lab Diamond Engagement Ring in 14K Rose Gold, shown on hand, angled | RockHer

The Brandi Select Solitaire Round Lab Diamond Engagement Ring in 14K Rose Gold

Select Solitaire Round · 14K Rose Gold

From $2,255

Lab Diamond Included
Caroline Select Three Stone Round Lab Diamond Engagement Ring in 18K White Gold, front view | RockHer

The Caroline Select Three Stone Round Lab Diamond Engagement Ring in 18K White Gold

Select Three Stone Round · 18K White Gold

From $4,350

Lab Diamond Included
Celesta Select Channel Set Round Lab Diamond Engagement Ring in 18K Yellow Gold, on hand, angled | RockHer

The Celesta Select Channel Set Round Lab Diamond Engagement Ring in 18K Yellow Gold

Select Channel Set Round · 18K Yellow Gold

From $4,700

Lab Diamond Included
The Grace emerald engagement ring setting in Platinum | RockHer

The Grace Select Solitaire Emerald Cut Lab Diamond Engagement Ring in Platinum

Select Solitaire Emerald Cut · Platinum

From $4,150

Lab Diamond Included
Dusty Select Hidden Halo Solitaire Oval Lab Diamond Engagement Ring in 14K Rose Gold, side view | RockHer

The Dusty Select Hidden Halo Solitaire Oval Lab Diamond Engagement Ring in 14K Rose Gold

Select Hidden Halo Solitaire Oval · 14K Rose Gold

From $4,015

Lab Diamond Included
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Complete Lab Diamond Engagement Rings Made to Order in Los Angeles

RockHer Select engagement rings arrive complete: a made to order setting in solid gold or platinum with an IGI certified lab grown diamond already matched and set by our gemologists, each one scored by ROSI™, gemological intelligence, before it ships. One fair price, a 40 day return window on eligible pieces, one complimentary resize within 60 days of delivery, up to 1.5 sizes (U.S.), and a lifetime warranty against manufacturing defects.

Speak with a Gemologist

Not sure where to begin?

One conversation with a gemologist replaces a hundred open tabs. We will guide you the way we would guide a close friend.

John Anderson · Lead Gemologist · (800) 779-1726

Book a Consultation

3 Carat Lab Grown Diamond Rings

A true statement diamond. A lab grown diamond puts three carats within reach without compromising on certification or beauty. Every ring on this page is a Select ring: the IGI certified diamond is already matched to the setting and included in the price, made to order in our Los Angeles atelier in platinum or solid gold.

One fair price, complimentary insured U.S. shipping, and a lifetime warranty against manufacturing defects.

3 Carat

3 Carat Lab Grown Diamond Rings

The rings on this page are complete: an IGI certified lab diamond already set, with 3 carat as one of the carat weights you can choose on the ring page. A 3 carat round measures about 9.3 mm across; the same weight spreads to about 11.5 × 8 as an oval and 9.5 × 7.5 as an emerald cut, because carat is weight, not size.

Every ring is made to order in our Los Angeles atelier, modeled around the exact measurements of the diamond before it is made. If you would rather a natural diamond, the same settings are built around a GIA certified 3 carat diamond through the configurator, where you choose the diamond first.

9.3 mm
Round
11.5 × 8
Oval
8 × 8
Cushion
9.5 × 7.5
Emerald
12 × 8
Pear

One fair price

The ring page shows one price for the complete ring at each carat weight. No codes, no strikethroughs, no timing the purchase.

IGI and GIA certified

Lab diamonds graded by IGI, natural diamonds graded by GIA. Our gemologist verifies every diamond against its certificate before it is set.

Resizing and warranty

60 day complimentary resizing, lifetime warranty, and the Ring Size Guide before you order.

Two ways to own one

Choose a complete ring below. Pick the design, the metal and the carat weight on the ring page. The lab diamond is already matched to the setting.

Build it around a natural diamond. Choose a GIA certified 3 carat diamond from our inventory, with a ROSI™ Score Report on any diamond you are considering, and John Anderson, our Lead Gemologist, reviews the shortlist with you before the setting is modeled to it.

All Select Rings Build Your Ring

Two 3 carat diamonds with the same certificate can look like different diamonds on the hand. Cut is where the difference lives, and it is the one grade worth paying for. Color and clarity above what the eye can see are paid for and never seen.

Talk to a jeweler before you decide

John Anderson, our Lead Gemologist, compares the candidates with you on the phone or by video. Call 1-800-779-1726 or request a consultation. There is no charge and no obligation.

Frequently Asked Questions

How big is a 3 carat diamond?

A well cut 3 carat round measures about 9.3 mm across, an oval about 11.5 × 8, a cushion about 8 × 8, an emerald cut about 9.5 × 7.5, a pear about 12 × 8. Carat is weight, so the exact measurements for any diamond are on its certificate.

Are the rings on this page natural or lab diamonds?

The complete rings shown here are IGI certified lab diamond rings, with 3 carat as one of the carat weights you can choose. The same settings are made around a GIA certified natural 3 carat diamond through our configurator, where you choose the diamond first and the setting is modeled to it.

Which grades should I choose at 3 carat?

Cut first: Excellent on the certificate for a round, or a reviewed cut for a fancy shape. G color or better in platinum and white gold, H or better in yellow and rose gold. VS2 or better clarity. Higher color and clarity grades than these are not visible on the hand.

How long does a 3 carat diamond ring take to make?

8 to 12 business days from the day the diamond is confirmed. The CAD model is built around the measurements on the certificate, the diamond is verified against the certificate by our gemologist, and the ring is finished and inspected in Los Angeles before it ships insured.