How much does a 5.00ct+ E SI1 lab grown cushion diamond cost?

As of October 2026, 5.00ct+ E SI1 lab grown cushion diamonds typically cost $937 AUD to $6,039 AUD, with a median price of $1,863 AUD. There are currently 34 diamonds matching this specification available across retailers.

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

About 50% of these diamonds are available at multiple retailers, with an average price spread of 114%. A comparison tool like Carat Hunter lets you see all the prices side by side.

5.00ct+ E SI1 Lab Grown Cushion

Quick answer

As of October 2026, there are 34 lab grown cushion diamonds with E colour and SI1 clarity in the 5.00ct+ range available across retailers worldwide. Prices typically run $937 AUD to $6,039 AUD, with a median of $1,863 AUD. At least 14 retailers stock this exact specification, and 50% of the stones appear at more than one of them, with an average price spread of 114%. Half of all listings fall between $396 AUD and $1,113 AUD per carat. The same specification in natural form lists at a median of about $31,402 AUD per carat.

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

$911 AUD

Highest Price

$590,364 AUD

Average Price

$12,031 AUD

Market Intelligence

Retailers Selling

Cross Retailer %

50.0%

Price Spread

113.8%

Price Range

Price per carat distribution across retailers

$443/ct

10th Percentile

$213

Median

$443

90th Percentile

$1,184

Score Distribution

83 diamonds scored across 4 quality tiers

Excellent

26 (31.3%)

Very Good

11 (13.3%)

Good

22 (26.5%)

Average

24 (28.9%)

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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