How much does a 0.20 to 0.49ct I SI2 natural radiant diamond cost?

As of October 2026, 0.20 to 0.49ct I SI2 natural radiant diamonds typically cost $571 NZD to $1,084 NZD, with a median price of $858 NZD. There are currently 13 diamonds matching this specification available across retailers.

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

About 15% of these diamonds are available at multiple retailers, with an average price spread of 32%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.20 to 0.49ct I SI2 Natural Radiant

Quick answer

As of October 2026, there are 13 natural radiant diamonds with I colour and SI2 clarity in the 0.20 to 0.49ct range available across retailers worldwide. Prices typically run $571 NZD to $1,084 NZD, with a median of $858 NZD. At least 35 retailers stock this exact specification, and 15% of the stones appear at more than one of them, with an average price spread of 32%. Half of all listings fall between $1,768 NZD and $2,450 NZD per carat. Over the last 30 days the median price moved -1.5% and the number of listings moved +3.6%.

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

$305 NZD

Highest Price

$2,393 NZD

Average Price

$846 NZD

Market Intelligence

Retailers Selling

Cross Retailer %

15.2%

Price Spread

32.2%

30-Day Price Trend

-1.5%

30-Day Supply Change

+3.6%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$1,190/ct

10th Percentile

$801

Median

$1,190

90th Percentile

$1,664

Score Distribution

47 diamonds scored across 4 quality tiers

Excellent

5 (10.6%)

Very Good

1 (2.1%)

Good

12 (25.5%)

Average

29 (61.7%)

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

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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