How much does a 5.00ct+ I SI1 natural round diamond cost?

As of September 2026, 5.00ct+ I SI1 natural round diamonds typically cost HK$427,569 HKD to HK$1,283,925 HKD, with a median price of HK$715,654 HKD. There are currently 315 diamonds matching this specification available across retailers.

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

Compare prices across retailers on Carat Hunter to see all your options.

5.00ct+ I SI1 Natural Round

Quick answer

As of September 2026, there are 315 natural round diamonds with I colour and SI1 clarity in the 5.00ct+ range available across retailers worldwide. Prices typically run HK$427,569 HKD to HK$1,283,925 HKD, with a median of HK$715,654 HKD. At least 5 retailers stock this exact specification. Half of all listings fall between HK$95,007 HKD and HK$147,067 HKD per carat. The same specification in lab grown form lists at a median of about HK$9,498 HKD per carat.

Three of the best scored stones at this specification right now:

Caratlytics Diamond Price Index, August 2026: natural diamonds at 2,184 USD per carat and lab-grown at 464 USD per carat, a natural to lab ratio of 4.7 to 1. Round natural stones in the index: 2,094 USD per carat, -3.8% month on month. See the full index release

Figures come from live listings across more than 100 retailers and refresh daily. The index is a monthly release.

Last updated: September 2026

Available

315

Lowest Price

HK$195,442 HKD

Highest Price

HK$4,014,916 HKD

Average Price

HK$841,709 HKD

Market Intelligence

Retailers Selling

Price Spread

40.1%

Price Range

Price per carat distribution across retailers

$16,887/ct

10th Percentile

$11,259

Median

$16,887

90th Percentile

$20,569

Score Distribution

315 diamonds scored across 4 quality tiers

Excellent

56 (17.8%)

Very Good

75 (23.8%)

Good

106 (33.7%)

Average

78 (24.8%)

Find Your Diamond

Search 315 I SI1 round 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 90%

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