How much does a 1.50 to 1.99ct H SI1 natural oval diamond cost?

As of October 2026, 1.50 to 1.99ct H SI1 natural oval diamonds typically cost £4,198 GBP to £10,456 GBP, with a median price of £6,093 GBP. There are currently 404 diamonds matching this specification available across retailers.

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

About 33% of these diamonds are available at multiple retailers, with an average price spread of 43%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct H SI1 Natural Oval

Quick answer

As of October 2026, there are 404 natural oval diamonds with H colour and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run £4,198 GBP to £10,456 GBP, with a median of £6,093 GBP. At least 62 retailers stock this exact specification, and 33% of the stones appear at more than one of them, with an average price spread of 43%. Half of all listings fall between £2,933 GBP and £4,486 GBP per carat. The same specification in lab grown form lists at a median of about £822 GBP per carat. Over the last 30 days the median price moved -1.8% and the number of listings moved +3.3%.

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 natural stones in the index: 2,655 USD per carat, +10.2% 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

404

Lowest Price

£2,151 GBP

Highest Price

£16,342 GBP

Average Price

£6,777 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

32.9%

Price Spread

43.0%

30-Day Price Trend

-1.8%

30-Day Supply Change

+3.3%

Volatility (30d)

0.00

Price Range

Price per carat distribution across retailers

$4,811/ct

10th Percentile

$3,129

Median

$4,811

90th Percentile

$7,230

Score Distribution

1.2K diamonds scored across 4 quality tiers

Excellent

58 (4.7%)

Very Good

242 (19.7%)

Good

246 (20.0%)

Average

681 (55.5%)

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Consider Instead

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

H SI2SI2 inclusions are not visible without magnification

Save 24%

Lab-Grown H SI1Same specifications, lab-grown origin

Save 77%

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