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

As of October 2026, 1.50 to 1.99ct D SI1 natural cushion diamonds typically cost $6,686 AUD to $21,739 AUD, with a median price of $12,323 AUD. There are currently 167 diamonds matching this specification available across retailers.

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

About 28% of these diamonds are available at multiple retailers, with an average price spread of 55%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct D SI1 Natural Cushion

Quick answer

As of October 2026, there are 167 natural cushion diamonds with D colour and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run $6,686 AUD to $21,739 AUD, with a median of $12,323 AUD. At least 59 retailers stock this exact specification, and 28% of the stones appear at more than one of them, with an average price spread of 55%. Half of all listings fall between $5,479 AUD and $9,440 AUD per carat. The same specification in lab grown form lists at a median of about $608 AUD per carat. Over the last 30 days the median price moved -2.6% and the number of listings moved +4.4%.

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. Cushion natural stones in the index: 2,948 USD per carat, +1.7% 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

167

Lowest Price

$4,100 AUD

Highest Price

$35,973 AUD

Average Price

$13,333 AUD

Market Intelligence

Retailers Selling

Cross Retailer %

27.6%

Price Spread

55.0%

30-Day Price Trend

-2.6%

30-Day Supply Change

+4.4%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$5,062/ct

10th Percentile

$3,018

Median

$5,062

90th Percentile

$8,230

Score Distribution

486 diamonds scored across 4 quality tiers

Excellent

65 (13.4%)

Very Good

68 (14.0%)

Good

123 (25.3%)

Average

230 (47.3%)

Find Your Diamond

Search 167 D SI1 cushion diamonds and compare prices.

Search Diamonds

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

Save 22%

Lab-Grown D SI1Same specifications, lab-grown origin

Save 92%

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