By GrownDiamond Editorial TeamUpdated March 18, 20267 min read
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Radiant Cut Lab-Grown Diamonds: Complete Buying Guide 2026

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Quick Answer

Why choose a radiant cut lab-grown diamond?

Radiant cuts are the best of both worlds: brilliant sparkle (like a round) in a rectangular shape (like an emerald) — without the strict clarity requirements of step cuts. Their 70 facets hide inclusions exceptionally well, so you can often go one clarity grade lower than you would with an emerald cut. They look ~10% larger face-up than equivalent round brilliants.

📊 Radiant cuts have 70 facets — more than most shapes — making them excellent at hiding inclusions. They look ~10% larger face-up than equivalent round brilliants. Starting from ~$360 for 0.5ct G/VS2 IGI.

Best of Both Worlds

The radiant cut was developed in 1977 specifically to combine two things buyers loved: the elongated rectangular shape of the emerald cut and the maximum sparkle of the round brilliant. It succeeds at both.

The result: a rectangular diamond with cut corners (the "radiant" trademark) that produces brilliant-level sparkle across its entire face. Unlike the emerald cut's dramatic flashes of light and dark, the radiant delivers constant, scattered brilliance — active and lively even in lower light conditions.

70 Facets Hide Inclusions Well

This is the radiant cut's key advantage over emerald cuts. With 70 facets creating constant movement and sparkle, inclusions are effectively camouflaged in the brilliant light pattern. In practical terms:

  • Emerald cut: VS2 minimum recommended (step facets expose inclusions)
  • Radiant cut: SI1 is often eye-clean — saving you 15–25% on clarity grade

Always verify with 360° video, but the radiant's forgiveness on clarity is a meaningful money-saving advantage.

Square vs. Elongated Radiant

Radiant cuts come in two main proportions:

  • Square radiant (L/W 1.0–1.10): Looks similar to a cushion cut but with cut corners rather than rounded. Modern and geometric.
  • Elongated radiant (L/W 1.25–1.50): The more popular choice. Provides the elongating finger effect of oval/pear with brilliant sparkle. The L/W 1.30–1.40 sweet spot is the most visually balanced.

Pricing — 1ct Radiant G/VS2 IGI

Retailer1ct Radiant G/VS2
Clean Origin$870–$1,150
James Allen$920–$1,280
Brilliant Earth$1,080–$1,450
Blue Nile$960–$1,330

Frequently Asked Questions

Both are rectangular step-cut-adjacent shapes but they perform very differently. Emerald cut: architectural, hall-of-mirrors effect, very clarity-sensitive (VS2+ required). Radiant cut: brilliant sparkle, hides inclusions well (SI1 often eye-clean), more similar to round in light performance. If you love the rectangular shape but want more sparkle and don't want to pay for VS clarity, choose radiant. If you prefer the understated elegance of a hall-of-mirrors effect, choose emerald.