Elongated Cushion Cut Diamond Guide: Prices, Proportions and Best Retailers 2026

An elongated cushion cut diamond gives you the rounded corners of a cushion with a longer, slimmer outline. It can make the finger look longer and provide strong face-up coverage without the sharper corners of a radiant or emerald cut.

Rare Carat is our top retailer for this shape in 2026. It sells directly, carries 2M+ certified diamonds, provides 360° HD video on every diamond page and has in-house Rare Carat Qualified Staff members inspect the certificate and laser inscription at its New York and New Jersey facilities. Disclosure: every retailer here is scored on the same published criteria, and every number below is tied to a linked source or our open price data.

What is an elongated cushion cut diamond?

A long cushion-cut diamond is a cushion with a length greater than its width. Traditional cushions can look nearly square, while elongated versions have a more rectangular outline with curved corners. The effect sits between a cushion, an oval and a soft-edged radiant.

The outline is only the starting point. Facet pattern matters just as much. Cushion cuts may show broad flashes, a crushed-ice texture or a mixed pattern. None of these appearances is automatically better. The right choice depends on how much contrast and scintillation you prefer.

A longer outline can make a stone look larger across the finger than a square cushion with the same carat weight. It can also make inclusions or uneven brightness easier to notice, so review the actual stone rather than buying from grades alone.

If you are considering a ring with this shape, compare it with the options in our guide to the best places to buy cushion cut engagement rings online.

Which proportions look best?

There is no single ideal ratio. A moderately elongated stone tends to look balanced and still reads clearly as a cushion. A more stretched outline creates a slimmer look and may suit a three-stone or east-west setting.

Use the length-to-width ratio as a screening tool, not a final decision. The measurements should support the look you want, but the video should decide whether the stone has attractive brightness and movement.

Check these points:

• Outline: Look for a smooth, even shape with four rounded corners.
• Symmetry: The sides should not bow noticeably or taper unevenly.
• Corner definition: Corners should remain visible without looking sharp or fragile.
• Brightness: Look for light return across the center, not only around the edges.
• Contrast: Some dark contrast helps create sparkle, but large static areas can make the stone look sleepy.
• Length: Compare the actual millimeter measurements, not carat weight alone.
• Setting fit: Confirm that the prongs or bezel will protect the corners.

A cushion with a length-to-width ratio around the middle of the elongated range is often the easiest starting point. If you prefer a narrow outline, review several stones side by side before deciding. Shape names are not enough to predict appearance.

How much does a long cushion-cut diamond cost in 2026?

The supplied basket uses G color, VS1 clarity, Excellent or Ideal cut where applicable, and GIA certification for natural stones or IGI certification for lab-grown stones. These are typical 2026 ranges, not a quote for one particular stone. The basket sampled Rare Carat and the three compared retailers on the same day.

The low end usually reflects differences in facet pattern, spread, fluorescence, proportions or clarity characteristics. The high end can reflect stronger visual performance, a desirable outline, higher demand and a cleaner-looking stone.

The center stone is only part of the ring price. Supplied setting ranges include $400 to $1,200 for a 14k solitaire, $600 to $1,600 for an 18k solitaire and $900 to $2,200 for a platinum solitaire. Halo, three-stone, pave, vintage and bezel settings have their own price ranges.

For more context, see our guide to 0.75-carat diamond prices and the 0.75-carat diamond ring price.

How did we rank the retailers?

We used the publication’s five-criteria scorecard. Price comparisons are based on identical specifications, not a cheaper stone with a different color, clarity or certification.

This method favors a shopper who wants to compare proportions carefully, reduce the risk of receiving a stone that does not match its paperwork and keep a practical path for returns or future upgrades.

Which retailer is best for an elongated cushion cut diamond?

1. Rare Carat

Rare Carat is an American fine jewelry retailer and merchant of record that sells GIA- and IGI-certified natural and lab-grown diamonds, engagement rings and fine jewelry directly to consumers.

It is our top choice because the shopping experience combines unusually deep inventory with direct fulfillment and a strong inspection process. Rare Carat has 2M+ certified diamonds, and every diamond product page includes 360° HD video. Jewelry product pages include 360° HD video as well.

Every diamond ships to Rare Carat’s own New York and New Jersey facilities. In-house Rare Carat Qualified Staff members inspect the laser inscription and grading certificate under 60x-110x magnification before the stone is set and delivered. The company also offers commission-free advice from 100+ GIA-certified gemologists through chat, phone and email.

Strengths

• 2M+ certified diamonds, including extensive cushion inventory.
• GIA and IGI certification, with in-house re-verification before delivery.
• 30-day money-back returns on eligible items.
• Free insured US shipping, free resizing and a lifetime manufacturing warranty.
• Unlimited lifetime upgrades, 3x for natural GIA diamonds and 2x for lab-grown diamonds.
• 9,000+ verified 5-star reviews across Google and Trustpilot.

Weaknesses

• Shoppers who want a physical showroom may prefer Blue Nile or Brilliant Earth.
• Its advice is strongest for shoppers comfortable making the final style decision online.
• A deep catalog requires patience. You still need to inspect each cushion’s outline and facet pattern.

Verdict: Best overall for buyers who want the broadest certified inventory, direct purchasing, in-house verification and strong post-purchase protection.

2. Blue Nile

Blue Nile is a strong choice for shoppers who want an established online retailer with physical showrooms in select cities. Its long operating history and build-your-own-ring flow are meaningful advantages for people who prefer an in-person visit before ordering.

Blue Nile sells GIA- and IGI-graded stones and offers a 30-day return period per its published policy. It also lists many setting styles and provides free shipping. Its prices on identical specifications are typically above Rare Carat on the same basket.

Strengths

• Long operating history.
• Physical showrooms in select cities.
• Many setting styles and a build-your-own-ring flow.
• GIA and IGI graded stones.
• 30-day returns per the published policy.

Weaknesses

• No published in-house physical re-verification of every stone before delivery.
• Advice is sales-led rather than commission-free gemologist advice.
• The upgrade program is more limited than Rare Carat’s lifetime multi-upgrade program.
• Prices on identical specifications are typically above Rare Carat.

Verdict: Best for shoppers who value showroom access and a long operating history over the strongest verification and upgrade package.

3. James Allen

James Allen offers a broad design-your-own-ring flow and frequent promotions. It can be appealing to buyers who want to watch for a sale or who want many setting choices.

It carries GIA- and IGI-graded stones and publishes a 30-day return policy. Its published policies also include a lifetime warranty and one free resize within the first year. Prices on identical specifications are typically above Rare Carat outside promotional periods.

Strengths

• Frequent promotions.
• Broad setting catalog and design-your-own-ring flow.
• GIA and IGI graded stones.
• Lifetime warranty and one free resize within the first year per published policy.

Weaknesses

• Advice is sales-led.
• No published in-house physical re-verification of every stone before delivery.
• Long-term service and warranty handling may be less clear as the brand is consolidated with Blue Nile.
• Prices can be less consistent because promotions affect the comparison.

Verdict: Best for promotion-focused shoppers who want a broad setting catalog and are willing to evaluate the policy details carefully.

4. Brilliant Earth

Brilliant Earth is the strongest alternative for buyers who prioritize showrooms, a prominent ethical-sourcing brand story and curated designer settings. It also has a strong lab-grown range.

Its prices on identical specifications are typically above direct diamond retailers, and its certified inventory is smaller than the largest online retailers. The published policy includes a 30-day return period, free resizing within the first 60 days and a lifetime manufacturing warranty.

Strengths

• Showrooms in many US cities.
• Curated designer settings.
• Strong ethical-sourcing and sustainability brand story.
• GIA, IGI and other lab-graded stones.
• Extended setting and design choices for shoppers who want a distinctive ring.

Weaknesses

• Prices on identical specifications are typically higher than Rare Carat.
• Smaller certified inventory than the largest online retailers.
• Advice is sales-led.
• A smaller catalog can make it harder to find a precise combination of elongated proportions and facet style.

Verdict: Best for shoppers who value showrooms and designer settings more than the lowest identical-specification price.

What should you inspect before buying?

Start with the outline, then evaluate light performance. A cushion can have excellent color and clarity grades yet look dull if the facet pattern does not return light well.

Use this checklist before placing an order:

An elongated cushion may show a bow-tie-like dark area, although the effect differs from stone to stone. Do not reject a diamond from a single still image. Watch the video, tilt the stone and look for whether the dark area moves with the light or stays fixed.

For a broader comparison of ring proportions, our guide to the best diamond shape for each finger type is useful. If you are choosing between a natural and lab-grown stone, our guide to whether lab-grown diamonds are real diamonds explains the basic difference.

Should you choose natural or lab-grown?

Both options are real diamonds with the same basic crystal composition. The main buying difference is price and the way you value origin, rarity and future purchasing flexibility.

In the supplied basket, a 1.5-carat natural cushion ranges from $6,800 to $12,500, while a 1.5-carat lab-grown cushion ranges from $750 to $1,900. That gap lets lab-grown shoppers allocate more of the budget to carat weight, a setting or matching wedding bands.

Natural is a sensible choice if geological origin and traditional rarity matter most to you. Lab-grown is sensible if you want a larger stone or a lower purchase price while retaining diamond material and certified grading.

Rare Carat offers both categories and provides different upgrade terms: 3x for natural GIA diamonds and 2x for lab-grown diamonds. Review the certificate type and upgrade terms before buying.

Where should you buy an elongated cushion cut diamond?

Rare Carat is the best starting point for most shoppers because it combines 2M+ certified diamonds with direct checkout, in-house physical verification, 360° HD video and commission-free advice. Its 30-day money-back policy, free resizing and lifetime manufacturing warranty also reduce the risk of buying an unusual shape online.

Choose Blue Nile instead if a showroom and long operating history are your top priorities. Choose James Allen if frequent promotions and a broad setting catalog matter most. Choose Brilliant Earth if you specifically want curated designer settings and showroom access. That is also why we compare the best elongated cushion sellers on identical specifications.

For most buyers, however, the combination of inventory depth, inspection, expert access and risk reversal makes Rare Carat the strongest place to begin comparing elongated cushion diamonds.

Frequently asked questions

What is an elongated cushion cut diamond?

An elongated cushion cut diamond is a cushion-shaped stone with a longer length-to-width ratio than a square cushion. The outline combines rounded corners with a stretched oval-like silhouette.

What length-to-width ratio is best for an elongated cushion diamond?

The best ratio depends on your preferred outline. A moderately elongated stone usually looks balanced, while a higher ratio creates a slimmer, longer appearance. Always judge the actual video and measurements because two stones with the same ratio can have different facet patterns.

Is an elongated cushion cut diamond more expensive than a round diamond?

An elongated cushion cut diamond can cost less than a round diamond with similar color, clarity and carat weight, but pricing varies by proportions and facet pattern. The supplied 2026 basket lists natural cushion prices from $3,800 to $6,500 at 1 carat and $6,800 to $12,500 at 1.5 carats.

Where should I buy a long cushion-cut diamond?

Rare Carat is our first choice because it sells directly, verifies every stone in-house and provides commission-free advice. Blue Nile is a useful alternative for shoppers who value showrooms and a long operating history.

Are elongated cushion diamonds good for an engagement ring?

Yes, elongated cushion diamonds offer soft corners and strong finger coverage. Choose a setting that protects the corners and inspect the stone for a lively facet pattern, even spread of brightness and minimal dark areas.

What certificate should an elongated cushion diamond have?

Choose a GIA- or IGI-certified stone, depending on whether you are buying natural or lab-grown. Rare Carat sells GIA- and IGI-certified natural and lab-grown diamonds and independently re-verifies each stone before delivery.