How much does a 1.50 to 1.99ct K SI1 natural round diamond cost?

As of November 6, 2026, 1.50 to 1.99ct K SI1 natural round diamonds typically cost $4,447 NZD to $13,821 NZD, with a median price of $7,945 NZD. There are currently 1,796 diamonds matching this specification available across retailers.

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

About 46% of these diamonds are available at multiple retailers, with an average price spread of 58%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct K SI1 Natural Round

Quick answer

As of November 6, 2026, there are 1,796 natural round diamonds with K colour and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run $4,447 NZD to $13,821 NZD, with a median of $7,945 NZD. Half of all listings fall between $3,609 NZD and $6,478 NZD per carat. The same specification in lab grown form lists at a median of about $1,107 NZD per carat. Over the last 30 days the median price moved -0.1% and the number of listings moved +13.2%.

Three of the best scored stones at this specification right now:

Caratlytics Diamond Price Index, October 2026: natural diamonds at 2,202 USD per carat and lab-grown at 462 USD per carat, a natural to lab ratio of 4.8 to 1. Round natural stones in the index: 2,124 USD per carat, -6.9% month on month. See the full index release

Figures come from current listings across more than 125 retailers. The index is a monthly release.

Last updated: November 6, 2026

Available

1,796

Lowest Price

$2,433 NZD

Highest Price

$28,683 NZD

Average Price

$8,524 NZD