How much does a 0.50 to 0.74ct I SI1 lab grown oval diamond cost?

As of October 2026, 0.50 to 0.74ct I SI1 lab grown oval diamonds typically cost £203 GBP to £346 GBP, with a median price of £228 GBP. There are currently 43 diamonds matching this specification available across retailers.

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

About 73% of these diamonds are available at multiple retailers, with an average price spread of 171%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.50 to 0.74ct I SI1 Lab Grown Oval

Quick answer

As of October 2026, there are 43 lab grown oval diamonds with I colour and SI1 clarity in the 0.50 to 0.74ct range available across retailers worldwide. Prices typically run £203 GBP to £346 GBP, with a median of £228 GBP. At least 25 retailers stock this exact specification, and 73% of the stones appear at more than one of them, with an average price spread of 171%. Half of all listings fall between £502 GBP and £1,527 GBP per carat. The same specification in natural form lists at a median of about £1,053 GBP per carat. Over the last 30 days the median price moved -3.2% and the number of listings moved -4.6%.

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. Oval lab grown stones in the index: 453 USD per carat, -7.4% 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

£95 GBP

Highest Price

£1,610 GBP

Average Price

£266 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

72.7%

Price Spread

170.6%

30-Day Price Trend

-3.2%

30-Day Supply Change

-4.6%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$799/ct

10th Percentile

$600

Median

$799

90th Percentile

$2,567

Score Distribution

43 diamonds scored across 4 quality tiers

Excellent

31 (72.1%)

Very Good

9 (20.9%)

Good

2 (4.7%)

Average

1 (2.3%)

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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