How much does a 1.00 to 1.49ct I SI2 natural radiant diamond cost?

As of October 2026, 1.00 to 1.49ct I SI2 natural radiant diamonds typically cost $2,102 AUD to $6,080 AUD, with a median price of $3,618 AUD. There are currently 159 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 56%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct I SI2 Natural Radiant

Quick answer

As of October 2026, there are 159 natural radiant diamonds with I colour and SI2 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run $2,102 AUD to $6,080 AUD, with a median of $3,618 AUD. At least 50 retailers stock this exact specification, and 33% of the stones appear at more than one of them, with an average price spread of 56%. Half of all listings fall between $2,367 AUD and $4,059 AUD per carat. Over the last 30 days the median price moved -0.2% and the number of listings moved +14.0%.

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

159

Lowest Price

$1,102 AUD

Highest Price

$9,690 AUD

Average Price

$3,843 AUD

Market Intelligence

Retailers Selling

Cross Retailer %

32.8%

Price Spread

55.8%

30-Day Price Trend

-0.2%

30-Day Supply Change

+14.0%

Volatility (30d)

0.00

Price Range

Price per carat distribution across retailers

$2,129/ct

10th Percentile

$1,366

Median

$2,129

90th Percentile

$3,758

Score Distribution

488 diamonds scored across 4 quality tiers

Excellent

67 (13.7%)

Very Good

81 (16.6%)

Good

95 (19.5%)

Average

245 (50.2%)

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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