How much does a 3.00 to 4.99ct I SI2 natural radiant diamond cost?

As of October 2026, 3.00 to 4.99ct I SI2 natural radiant diamonds typically cost $34,236 AUD to $119,199 AUD, with a median price of $57,981 AUD. There are currently 57 diamonds matching this specification available across retailers.

Where can I find the best price on a I SI2 radiant diamond?

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

3.00 to 4.99ct I SI2 Natural Radiant

Quick answer

As of October 2026, there are 57 natural radiant diamonds with I colour and SI2 clarity in the 3.00 to 4.99ct range available across retailers worldwide. Prices typically run $34,236 AUD to $119,199 AUD, with a median of $57,981 AUD. At least 42 retailers stock this exact specification, and 33% of the stones appear at more than one of them, with an average price spread of 33%. Half of all listings fall between $9,808 AUD and $13,839 AUD per carat. Over the last 30 days the median price moved -0.3% and the number of listings moved +9.3%.

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. 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

$14,469 AUD

Highest Price

$192,566 AUD

Average Price

$65,902 AUD

Market Intelligence

Retailers Selling

Cross Retailer %

33.2%

Price Spread

32.8%

30-Day Price Trend

-0.3%

30-Day Supply Change

+9.3%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$8,643/ct

10th Percentile

$5,082

Median

$8,643

90th Percentile

$10,962

Score Distribution

194 diamonds scored across 4 quality tiers

Excellent

35 (18.0%)

Very Good

35 (18.0%)

Good

22 (11.3%)

Average

102 (52.6%)

Find Your Diamond

Search 57 I SI2 radiant diamonds and compare prices.

Search Diamonds

Consider Instead

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

J SI2J colour is visually identical to I to the naked eye

Save 24%

I I1I1 inclusions are not visible without magnification

Save 18%

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