How much does a 0.20 to 0.49ct I SI1 natural heart diamond cost?

As of October 2026, 0.20 to 0.49ct I SI1 natural heart diamonds typically cost £235 GBP to £442 GBP, with a median price of £330 GBP. There are currently 86 diamonds matching this specification available across retailers.

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

About 25% of these diamonds are available at multiple retailers, with an average price spread of 51%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.20 to 0.49ct I SI1 Natural Heart

Quick answer

As of October 2026, there are 86 natural heart diamonds with I colour and SI1 clarity in the 0.20 to 0.49ct range available across retailers worldwide. Prices typically run £235 GBP to £442 GBP, with a median of £330 GBP. At least 12 retailers stock this exact specification, and 25% of the stones appear at more than one of them, with an average price spread of 51%. Half of all listings fall between £855 GBP and £1,359 GBP 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. Heart natural stones in the index: 2,374 USD per carat, +9.8% 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

£93 GBP

Highest Price

£839 GBP

Average Price

£340 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

25.0%

Price Spread

50.8%

Price Range

Price per carat distribution across retailers

$1,328/ct

10th Percentile

$1,062

Median

$1,328

90th Percentile

$2,214

Score Distribution

210 diamonds scored across 4 quality tiers

Excellent

13 (6.2%)

Very Good

45 (21.4%)

Good

33 (15.7%)

Average

119 (56.7%)

Find Your Diamond

Search 86 I SI1 heart diamonds and compare prices.

Search Diamonds

Consider Instead

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

J SI1J colour is visually identical to I to the naked eye

Save 7%

I SI2SI2 inclusions are not visible without magnification

Save 13%

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