How much does a 0.75 to 0.99ct E SI1 lab grown cushion diamond cost?

As of October 2026, 0.75 to 0.99ct E SI1 lab grown cushion diamonds typically cost $300 AUD to $1,435 AUD, with a median price of $625 AUD. There are currently 29 diamonds matching this specification available across retailers.

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

About 40% of these diamonds are available at multiple retailers, with an average price spread of 88%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.75 to 0.99ct E SI1 Lab Grown Cushion

Quick answer

As of October 2026, there are 29 lab grown cushion diamonds with E colour and SI1 clarity in the 0.75 to 0.99ct range available across retailers worldwide. Prices typically run $300 AUD to $1,435 AUD, with a median of $625 AUD. At least 33 retailers stock this exact specification, and 40% of the stones appear at more than one of them, with an average price spread of 88%. Half of all listings fall between $558 AUD and $1,233 AUD per carat. The same specification in natural form lists at a median of about $3,030 AUD per carat. Over the last 30 days the median price moved -3.6% and the number of listings moved +3.8%.

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 lab grown stones in the index: 516 USD per carat, +6.9% 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

Lowest Price

$188 AUD

Highest Price

$2,700 AUD

Average Price

$800 AUD

Market Intelligence

Retailers Selling

Cross Retailer %

40.0%

Price Spread

88.1%

30-Day Price Trend

-3.6%

30-Day Supply Change

+3.8%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$538/ct

10th Percentile

$285

Median

$538

90th Percentile

$1,302

Score Distribution

74 diamonds scored across 4 quality tiers

Excellent

13 (17.6%)

Very Good

11 (14.9%)

Good

29 (39.2%)

Average

21 (28.4%)

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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