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

As of October 2026, 1.00 to 1.49ct I SI2 natural round diamonds typically cost $2,261 AUD to $6,817 AUD, with a median price of $3,637 AUD. There are currently 2,242 diamonds matching this specification available across retailers.

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

About 36% of these diamonds are available at multiple retailers, with an average price spread of 60%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct I SI2 Natural Round

Quick answer

As of October 2026, there are 2,242 natural round diamonds with I colour and SI2 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run $2,261 AUD to $6,817 AUD, with a median of $3,637 AUD. At least 67 retailers stock this exact specification, and 36% of the stones appear at more than one of them, with an average price spread of 60%. Half of all listings fall between $2,748 AUD and $4,787 AUD per carat. The same specification in lab grown form lists at a median of about $1,582 AUD per carat. Over the last 30 days the median price moved -0.1% and the number of listings moved +4.3%.

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. Round natural stones in the index: 2,248 USD per carat, +7.6% 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

2,242

Lowest Price

$1,173 AUD

Highest Price

$16,995 AUD

Average Price

$4,161 AUD