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

As of October 2026, 1.50 to 1.99ct D SI1 natural round diamonds typically cost $11,875 NZD to $34,726 NZD, with a median price of $19,186 NZD. There are currently 817 diamonds matching this specification available across retailers.

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

About 36% of these diamonds are available at multiple retailers, with an average price spread of 45%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct D SI1 Natural Round

Quick answer

As of October 2026, there are 817 natural round diamonds with D colour and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run $11,875 NZD to $34,726 NZD, with a median of $19,186 NZD. At least 65 retailers stock this exact specification, and 36% of the stones appear at more than one of them, with an average price spread of 45%. Half of all listings fall between $9,722 NZD and $15,141 NZD per carat. The same specification in lab grown form lists at a median of about $691 NZD per carat. Over the last 30 days the median price moved -1.6% and the number of listings moved +12.6%.

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. 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

817

Lowest Price

$6,877 NZD

Highest Price

$55,452 NZD

Average Price

$21,413 NZD

Market Intelligence

Retailers Selling

Cross Retailer %

35.8%

Price Spread

45.4%

30-Day Price Trend

-1.6%

30-Day Supply Change

+12.6%

Volatility (30d)

0.00

Price Range

Price per carat distribution across retailers

$6,694/ct

10th Percentile

$4,619

Median

$6,694

90th Percentile

$10,398

Score Distribution

2.1K diamonds scored across 4 quality tiers

Excellent

332 (16.0%)

Very Good

547 (26.4%)

Good

456 (22.0%)

Average

737 (35.6%)

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Consider Instead

Save money without compromising on what matters. These alternatives are visually similar but cost less.

D SI2SI2 inclusions are not visible without magnification

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Lab-Grown D SI1Same specifications, lab-grown origin

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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