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

As of October 2026, 1.50 to 1.99ct G SI1 natural round diamonds typically cost $5,741 USD to $15,870 USD, with a median price of $9,063 USD. There are currently 1,575 diamonds matching this specification available across retailers.

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

About 39% of these diamonds are available at multiple retailers, with an average price spread of 44%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct G SI1 Natural Round

Quick answer

As of October 2026, there are 1,575 natural round diamonds with G color and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run $5,741 USD to $15,870 USD, with a median of $9,063 USD. At least 69 retailers stock this exact specification, and 39% of the stones appear at more than one of them, with an average price spread of 44%. Half of all listings fall between $4,969 USD and $7,679 USD per carat. The same specification in lab grown form lists at a median of about $380 USD per carat. Over the last 30 days the median price moved -1.9% and the number of listings moved +15.4%.

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

1,575

Lowest Price

$3,119 USD

Highest Price

$27,356 USD

Average Price

$10,073 USD