How much does a 0.50 to 0.74ct I SI1 natural heart diamond cost?

As of October 2026, 0.50 to 0.74ct I SI1 natural heart diamonds typically cost £291 GBP to £743 GBP, with a median price of £437 GBP. There are currently 246 diamonds matching this specification available across retailers.

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

About 33% of these diamonds are available at multiple retailers, with an average price spread of 37%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.50 to 0.74ct I SI1 Natural Heart

Quick answer

As of October 2026, there are 246 natural heart diamonds with I colour and SI1 clarity in the 0.50 to 0.74ct range available across retailers worldwide. Prices typically run £291 GBP to £743 GBP, with a median of £437 GBP. At least 55 retailers stock this exact specification, and 33% of the stones appear at more than one of them, with an average price spread of 37%. Half of all listings fall between £658 GBP and £945 GBP per carat. The same specification in lab grown form lists at a median of about £420 GBP per carat. Over the last 30 days the median price moved -1.7% and the number of listings moved +2.7%.

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

246

Lowest Price

£251 GBP

Highest Price

£1,501 GBP

Average Price

£506 GBP

Market Intelligence

Retailers Selling

Cross Retailer %

33.1%

Price Spread

37.0%

30-Day Price Trend

-1.7%

30-Day Supply Change

+2.7%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$1,041/ct

10th Percentile

$775

Median

$1,041

90th Percentile

$1,868

Score Distribution

653 diamonds scored across 4 quality tiers

Excellent

109 (16.7%)

Very Good

99 (15.2%)

Good

192 (29.4%)

Average

253 (38.7%)

Find Your Diamond

Search 246 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.

Lab-Grown I SI1Same specifications, lab-grown origin

Save 46%

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