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

As of October 2026, 0.50 to 0.74ct I SI1 natural cushion diamonds typically cost $576 AUD to $1,919 AUD, with a median price of $847 AUD. 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 October 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 $576 AUD to $1,919 AUD, with a median of $847 AUD. 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 $1,223 AUD and $2,305 AUD per carat. Over the last 30 days the median price moved +3.1% and the number of listings moved -2.2%.

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: October 2026

Available

103

Lowest Price

$403 AUD

Highest Price

$4,035 AUD

Average Price

$1,059 AUD

Market Intelligence

Retailers Selling

Cross Retailer %

24.4%

Price Spread

67.1%

30-Day Price Trend

+3.1%

30-Day Supply Change

-2.2%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$1,133/ct

10th Percentile

$720

Median

$1,133

90th Percentile

$2,154

Score Distribution

289 diamonds scored across 4 quality tiers

Excellent

43 (14.9%)

Very Good

54 (18.7%)

Good

103 (35.6%)

Average

89 (30.8%)

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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