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

As of October 2026, 5.00ct+ I SI1 natural radiant diamonds typically cost HK$510,313 HKD to HK$1,861,120 HKD, with a median price of HK$788,498 HKD. There are currently 25 diamonds matching this specification available across retailers.

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

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

5.00ct+ I SI1 Natural Radiant

Quick answer

As of October 2026, there are 25 natural radiant diamonds with I colour and SI1 clarity in the 5.00ct+ range available across retailers worldwide. Prices typically run HK$510,313 HKD to HK$1,861,120 HKD, with a median of HK$788,498 HKD. The same specification in lab grown form lists at a median of about HK$2,926 HKD 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. Radiant natural stones in the index: 3,091 USD per carat, +13.2% 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

Lowest Price

HK$260,258 HKD

Highest Price

HK$3,377,887 HKD

Average Price

HK$1,064,577 HKD

Score Distribution

57 diamonds scored across 4 quality tiers

Excellent

7 (12.3%)

Very Good

12 (21.1%)

Good

15 (26.3%)

Average

23 (40.4%)

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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