How much does a 1.00 to 1.49ct G SI1 lab grown princess diamond cost?

As of October 2026, 1.00 to 1.49ct G SI1 lab grown princess diamonds typically cost £283 GBP to £685 GBP, with a median price of £386 GBP. There are currently 31 diamonds matching this specification available across retailers.

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

About 27% of these diamonds are available at multiple retailers, with an average price spread of 86%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct G SI1 Lab Grown Princess

Quick answer

As of October 2026, there are 31 lab grown princess diamonds with G colour and SI1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run £283 GBP to £685 GBP, with a median of £386 GBP. At least 30 retailers stock this exact specification, and 27% of the stones appear at more than one of them, with an average price spread of 86%. Half of all listings fall between £184 GBP and £459 GBP per carat. The same specification in natural form lists at a median of about £2,188 GBP per carat. Over the last 30 days the median price moved -0.2% and the number of listings moved +14.4%.

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. Princess lab grown stones in the index: 461 USD per carat, -4.8% 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

£102 GBP

Highest Price

£1,239 GBP

Average Price

£459 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

26.8%

Price Spread

86.4%

30-Day Price Trend

-0.2%

30-Day Supply Change

+14.4%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$424/ct

10th Percentile

$176

Median

$424

90th Percentile

$857

Score Distribution

64 diamonds scored across 4 quality tiers

Excellent

4 (6.3%)

Very Good

6 (9.4%)

Good

21 (32.8%)

Average

33 (51.6%)

Find Your Diamond

Search 31 G SI1 princess diamonds and compare prices.

Search Diamonds

Consider Instead

Save money without compromising on what matters. These alternatives are visually similar but cost less.

G SI2SI2 inclusions are not visible without magnification

Save 6%

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