CaratHunter
Plans

Carat Hunter · Where to buy diamonds

0.5ct · I · SI1 · Marquise · 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

63

Retailers carrying

13

Price range

NZ$235 to
NZ$612

Median confirmed price

NZ$491

Certificate mix:IGI 54

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.

  3. 3NZ Jewellers7 in stock
    New Zealand·Founded 2006·IGI·30-day returns·Ships to New Zealand
    Terms read on the retailer’s own site, October 19, 2026
    Visit NZ Jewellers
  4. 4

    The Perfect Carat

    7 in stock
    US·IGI
    Terms not yet verified
Show 3 more retailers
  2. 12B2C Jewels1 in stock
    United States·Founded 2004·IGI·30-day returns·Ships to New Zealand
    Terms read on the retailer’s own site, October 19, 2026
    Visit B2C Jewels

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 63 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 0.5ct lab grown marquise diamond, all grades

How pricing is spread at this spec

For the 8 diamonds at this spec with a recently confirmed price, each taken at its cheapest confirmed price, the distribution looks like this:

  • Lowest confirmed
    NZ$235
  • 10th percentile
    NZ$259
  • Median
    NZ$491
  • 75th percentile
    NZ$501
  • 90th percentile
    NZ$548
  • Highest confirmed
    NZ$612

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 NZ$259. Use the explorer to sort by price.

Sort by price

Best cut quality for the spec?

11 of 63 active listings carry Excellent or Ideal across cut, polish and symmetry.

View top-cut subset

Want None or Faint fluorescence?

62 of 63 are graded None or Faint at this spec.

Shopping from New Zealand?

7 of the 11 retailers with shipping details ship to New Zealand. 4 do not. 2 retailers have not published any shipping details.

What this spec means

  • Marquise: a pointed-end ellipse that faces up large for its carat.
  • I colour: near-colourless, 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 0.5ct I SI1 marquise lab grown diamonds.

Compare Aurelinne vs Carbon Sparkle

Related specs

Slightly larger carat

marquise-0-75ct-i-si1-lab

One colour grade higher

marquise-0-5ct-h-si1-lab

One colour grade lower

marquise-0-5ct-j-si1-lab

One clarity grade higher

marquise-0-5ct-i-vs2-lab

One clarity grade lower

marquise-0-5ct-i-si2-lab

Same spec, natural

marquise-0-5ct-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 0.5ct I SI1 Marquise Lab Grown Diamonds | Carat Hunter