Cushion Lab Grown Diamond Three Stone Engagement Ring (1.78 ct, Trillion Sides)

IGI Report IncludedMade to OrderInsured Delivery

1 of 11

$673.00

Price updates with your selections

Independently graded by IGI IGI Report Included Selected 0.50 ct+ lab-grown center or primary diamond · IGI grading report · Signora Jewelry Certificate included. 1 ct lab-grown diamond · IGI report · Signora Certificate included.

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Center Diamond:

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Complimentary · hand-engraved to order · adds about 3–4 days.

Estimated dispatch: 7 business days Duties & taxes prepaid

Ring size guide

Lay a ring you own flat on the circle and slide until it sits just inside it — or set its inner diameter directly.

Measure the inside of a ring that already fits — inner edge to edge — with a ruler in mm, then set it below. No ring handy? Try Measure your finger.

14 mm 24 mm 17.3 mm

Inner diameter mm

US size

UK size

EU size

Circumference

54.3 mm

Between sizes? Always choose the larger size. Fingers are slightly bigger in the evening — measure then for the best fit.

Method 1 — Use an existing ring

Find a ring that fits the intended finger comfortably.
Place it flat and measure the inner diameter (inside edge to inside edge) in mm.
Enter that measurement in the Measure a ring tab.

Method 2 — Wrap and measure

Wrap a thin strip of paper around the base of your finger.
Mark where it overlaps — measure that length in mm (your circumference).
Divide by 3.1416 (π) to get your diameter, then use the Measure a ring tab.

Tip: Middle finger sizes typically run half a size larger than the ring finger. If between sizes, go up. Measure in the evening — fingers are slightly larger then.

7US size

US	UK	EU	Diameter	Circumference

Highlighted row = your converted size. Most common women's sizes are US 6–7. All measurements in mm.

Selected: —

The Signora Promise

Hand-finished in SuratMade to order

Reports where statedExact scope shown

Insured deliverySigned & tracked

Secure checkoutShopify checkout

Standard-design returns30-day eligibility

Final inspectionChecked before dispatch

About This Ring

Cushion Cut · Three Stone

Center

Cushion Cut

Carat

1 ct

Customizable

Metal

Customizable

Setting

Three Stone

An independent IGI grading report is included when the selected individual lab-grown center or primary diamond is 0.50 ct or larger.

Each metal color is shown in the photos — pick your center size and metal in the options on this page.

Detail	In the Photos	Customizable
Center diamond	Cushion · Approx. 1.78 ct	Yes — 1.00 to 4.50 ct
Metal & Color	Every color shown	Yes — 11 options
Side diamonds	2 Trillion · Approx. 0.31 ct total	Included as shown
Total diamond weight	Approx. 2.09 ct	Varies with selected center size
Stone type	Lab Grown Diamond	Lab Grown Diamond

Shape	Size	Qty	Approx. Ct
Cushion	7.00 × 7.00 mm	1	1.78 ct
Trillion	3.75 × 3.75 mm	2	0.155 ct each
Total	-	3	Approx. 2.09 ct

AT A GLANCE

A cushion Lab Grown Diamond three stone engagement ring from Signora Jewels.

Features one approximately 1.78 ct cushion center diamond with two trillion side diamonds totaling approximately 0.31 ct.

Made to order in Sterling Silver, 9K, 14K and 18K yellow, white and rose gold, plus Platinum.

Made to order — the price updates with your selection. Want something fully bespoke? Customize your jewelry here.

A Cushion Lab Grown Diamond Three Stone Engagement Ring beautifully symbolizes your past, present and future. At the center, a cushion-cut diamond delivers soft corners, broad flashes of brilliance and a timeless silhouette, while trillion-cut side diamonds create an elegant taper that naturally draws the eye toward the center stone.

Every ring is individually crafted by Signora Jewels after your order is placed, allowing you to choose the perfect center diamond size and precious metal to suit your style. The balanced three-stone design offers exceptional sparkle while maintaining a refined profile that is comfortable enough for everyday wear.

The clean four-prong basket elevates the center diamond to maximize light return, while the matching trillion side stones add brilliance without overwhelming the graceful proportions of the ring.

Design Highlights

Customizable cushion center diamond from 1.00 to 4.50 ct
Two trillion lab grown side diamonds totaling approximately 0.31 ct
Classic three-stone engagement ring design
Four-prong center setting with matching side settings
Crafted in 11 precious metal options
Comfort-fit high polish shank
Made to order for every customer

Three beautifully balanced diamonds create a ring that feels both classic and contemporary. The soft cushion center paired with sharp trillion accents produces a striking contrast that catches light from every angle while keeping the focus on the center diamond.

Diamond & Ring Details

Specification	Details
Center Stone	Cushion · 7.00 × 7.00 mm · Approx. 1.78 ct (shown)
Side Stones	2 Trillion Diamonds · Approx. 0.155 ct each
Total Weight	Approx. 2.09 ct (3 Diamonds)
Setting	Four-prong center with three-prong trillion side settings
Finish	High Polish
Occasion	Engagement · Anniversary · Bridal

Measurements are approximate. The final center diamond measurements will vary according to the carat weight selected.

About Lab Grown Diamonds

The cushion cut combines softened corners with brilliant faceting to create bold flashes of light and exceptional fire. Its balanced outline gives the ring a timeless appearance while offering excellent brilliance across a wide range of carat sizes.

Every lab grown diamond from Signora Jewels is chemically, physically and optically identical to a mined diamond. Each stone is graded using the same international 4C standards and offers exceptional beauty, a documented origin.

Learn more about lab grown diamonds, explore our three stone engagement rings, or browse our complete engagement ring collection.

Metal, Care & Fit

Choose from Sterling Silver, 9K, 14K and 18K yellow, white or rose gold, or Platinum. Order your usual ring size for the best fit, and most precious metal versions can be professionally resized if needed. Clean with warm water, mild soap and a soft brush, avoid harsh chemicals and store the ring separately to preserve its finish.

FAQ

Can I choose a larger center diamond?
Yes. This design is available with center diamond sizes from 1.00 to 4.50 carats while maintaining the same elegant three-stone design.

What diamonds remain the same on every version?
The two trillion lab grown side diamonds remain included on every variation and total approximately 0.31 carats.

Are lab grown diamonds real diamonds?
Yes. They are chemically, physically and optically identical to mined diamonds and are graded using the same 4C standards.

What is the difference between 9K and 18K gold?
Both are solid gold. 18K contains more pure gold and has a richer color, while 9K offers excellent durability for everyday wear.

Can the ring be resized later?
Yes. Most gold and platinum versions can be professionally resized after purchase if your finger size changes.

How is the ring shipped?
Your ring is made to order and shipped fully insured with tracking, signature confirmation and a 30-day return policy.

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