Carat Hunter · Where to buy diamonds

3ct · I · SI1 · Cushion · Lab-grown

Every retailer carrying this exact spec, from our latest listings.

Updated November 6, 2026 · Independent. Zero affiliate revenue.

Market at this spec

Active listings

42

Retailers carrying

17

Price range

$905 to
$1,545

Median confirmed price

$1,170

Certificate mix:IGI 28 · GIA 9 · GCAL 4

Range and median take each diamond at this spec at its cheapest recently confirmed price. They are cohort statistics, not per-retailer pricing claims.

Every retailer that stocks this spec

Ranked by active inventory count. Selection is mechanical, not editorial.

  1. 1B2C Jewels11 in stock
    United States·Founded 2004·IGI·30-day returns·Ships to United States
    Terms read on the retailer’s own site, October 19, 2026
    Visit B2C Jewels
  2. 4Adiamor2 in stock
    United States·Founded 1999·GCAL, IGI·Ships to United States
    Terms not yet verified
    Visit Adiamor
  3. 6Jared2 in stock
    United States·Founded 1993·GIA·Ships to United States
    Terms not yet verified
    Visit Jared
  4. 8Rare Carat2 in stock
    United States·Founded 2016·GCAL, IGI·30-day returns·Ships to United States
    Terms read on the retailer’s own site, October 19, 2026
    Visit Rare Carat
  5. 9RockHer2 in stock
    United States·Founded 2016·IGI·Ships to United States
    Terms not yet verified
    Visit RockHer
Show 7 more retailers
  1. 11Yorxs2 in stock
    Germany·Founded 2011·GIA, IGI
    Terms not yet verified
    Visit Yorxs
  2. 12Zales2 in stock
    United States·Founded 1924·GIA·Ships to United States
    Terms not yet verified
    Visit Zales
  3. 13Allurez1 in stock
    United States·Founded 2010·Ships to United States
    Terms not yet verified
    Visit Allurez

Stock counts reflect current listings. Founded and shipping details come from public sources. Return terms are our summary of each retailer's own policy page, dated per retailer above. Retailers change their terms, so check the retailer's own returns and shipping pages before you buy.

Explore all 42 stones in this cohort

Stones at this spec now

Current examples carried by more than one retailer, so the comparison is real. Prices shown in USD.

See every 3ct lab grown cushion diamond, all grades

How pricing is spread at this spec

For the 15 diamonds at this spec with a recently confirmed price, each taken at its cheapest confirmed price, the distribution looks like this:

  • Lowest confirmed
    $905
  • 10th percentile
    $928
  • Median
    $1,170
  • 75th percentile
    $1,183
  • 90th percentile
    $1,491
  • Highest confirmed
    $1,545

Cohort distribution only. No retailer named adjacent to a dollar figure in this section.

How to pick

Lowest price floor for the spec?

The cheapest confirmed prices start around $928. Use the explorer to sort by price.

Sort by price

Best cut quality for the spec?

20 of 42 active listings carry Excellent or Ideal across cut, polish and symmetry.

View top-cut subset

Want None or Faint fluorescence?

42 of 42 are graded None or Faint at this spec.

Shopping from United States?

15 of the 16 retailers with shipping details ship to United States. 1 does not. 1 retailer has not published any shipping details.

What this spec means

  • Cushion: a softened-corner square or rectangle with a vintage feel.
  • I color: near-colorless, with a faint warm tint just detectable in larger stones.
  • SI1 clarity: Slightly Included 1. Inclusions noticeable at 10x. Often still eye-clean depending on placement.
  • Lab-grown: chemically identical to natural diamonds, typically at least 90% less than a comparable natural cohort from 1 carat up.

Compare the top retailers carrying this spec

Side-by-side facts for the two stores carrying the most 3ct I SI1 cushion lab grown diamonds.

Compare B2C Jewels vs Loose Grown Diamond

Related specs

Slightly smaller carat

cushion-2ct-i-si1-lab

One colour grade higher

cushion-3ct-h-si1-lab

One colour grade lower

cushion-3ct-j-si1-lab

One clarity grade higher

cushion-3ct-i-vs2-lab

One clarity grade lower

cushion-3ct-i-si2-lab

Same spec, natural

cushion-3ct-i-si1-natural

Frequently asked

Does Carat Hunter earn commission from these retailers?

No. We earn zero affiliate revenue from any retailer in our index.

How fresh is this data?

Listings refresh as we re-read each retailer, most of them every day. Static facts about each retailer refresh weekly.

Why is one retailer cheaper for the same certificate?

Markup and overhead vary by retailer. The same physical diamond can list at very different prices across stores. See our cross-retailer analysis for the structural reasons.

How is the retailer ranking calculated?

Strictly by active inventory count for this exact spec. The retailer carrying the most stones at the spec ranks first. There is no editorial input, weighting or affiliate consideration.

Why do you not show per-retailer prices on this page?

Prices vary per stone, not per store. Click through to any matched diamond and you will see every retailer's price on the exact same physical stone, which is the meaningful comparison.

Where to Buy 3ct I SI1 Cushion Lab Grown Diamonds | Carat Hunter