How much does a 0.50 to 0.74ct I SI1 natural cushion diamond cost?

As of November 2026, 0.50 to 0.74ct I SI1 natural cushion diamonds typically cost $718 NZD to $2,395 NZD, with a median price of $1,054 NZD. There are currently 103 diamonds matching this specification available across retailers.

Where can I find the best price on a I SI1 cushion diamond?

About 24% of these diamonds are available at multiple retailers, with an average price spread of 67%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.50 to 0.74ct I SI1 Natural Cushion

Quick answer

As of November 2026, there are 103 natural cushion diamonds with I colour and SI1 clarity in the 0.50 to 0.74ct range available across retailers worldwide. Prices typically run $718 NZD to $2,395 NZD, with a median of $1,054 NZD. At least 49 retailers stock this exact specification, and 24% of the stones appear at more than one of them, with an average price spread of 67%. Half of all listings fall between $1,525 NZD and $2,873 NZD per carat. Over the last 30 days the median price moved +2.7% and the number of listings moved -2.4%.

Three of the best scored stones at this specification right now:

Caratlytics Diamond Price Index, September 2026: natural diamonds at 2,335 USD per carat and lab-grown at 443 USD per carat, a natural to lab ratio of 5.3 to 1. Cushion natural stones in the index: 2,948 USD per carat, +1.7% month on month. See the full index release

Figures come from current listings across more than 100 retailers and refresh daily. The index is a monthly release.

Last updated: November 2026

Available

103

Lowest Price

$501 NZD

Highest Price

$5,029 NZD

Average Price

$1,316 NZD

Market Intelligence

Retailers Selling

Cross Retailer %

24.5%

Price Spread

67.1%

30-Day Price Trend

+2.7%

30-Day Supply Change

-2.4%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$1,133/ct

10th Percentile

$721

Median

$1,133

90th Percentile

$2,160

Score Distribution

288 diamonds scored across 4 quality tiers

Excellent

43 (14.9%)

Very Good

55 (19.1%)

Good

102 (35.4%)

Average

88 (30.6%)

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Related Specifications

D IF D VVS1 D VVS2 D VS1 D VS2 D SI1 E IF E VVS1 E VVS2 E VS1 E VS2 E SI1 F IF F VVS1 F VVS2 F VS1 F VS2 F SI1 G IF G VVS1 G VVS2 G VS1 G VS2 G SI1 H IF H VVS1 H VVS2 H VS1 H VS2 H SI1 I IF I VVS1 I VVS2 I VS1 I VS2 I SI1