How much does a 1.50 to 1.99ct I SI1 lab grown cushion diamond cost?

As of October 2026, 1.50 to 1.99ct I SI1 lab grown cushion diamonds typically cost €389 EUR to €2,969 EUR, with a median price of €1,055 EUR. There are currently 18 diamonds matching this specification available across retailers.

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

About 37% of these diamonds are available at multiple retailers, with an average price spread of 118%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct I SI1 Lab Grown Cushion

Quick answer

As of October 2026, there are 18 lab grown cushion diamonds with I colour and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run €389 EUR to €2,969 EUR, with a median of €1,055 EUR. At least 28 retailers stock this exact specification, and 37% of the stones appear at more than one of them, with an average price spread of 118%. Half of all listings fall between €322 EUR and €965 EUR per carat. The same specification in natural form lists at a median of about €3,329 EUR per carat. Over the last 30 days the median price moved -15.4% and the number of listings moved -3.1%.

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

€228 EUR

Highest Price

€7,492 EUR

Average Price

€1,807 EUR

Market Intelligence

Retailers Selling

Cross Retailer %

37.1%

Price Spread

117.8%

30-Day Price Trend

-15.4%

30-Day Supply Change

-3.1%

Volatility (30d)

0.05

Price Range

Price per carat distribution across retailers

$610/ct

10th Percentile

$281

Median

$610

90th Percentile

$3,074

Score Distribution

30 diamonds scored across 4 quality tiers

Excellent

10 (33.3%)

Very Good

4 (13.3%)

Good

7 (23.3%)

Average

9 (30.0%)

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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