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

As of October 2026, 1.50 to 1.99ct F SI1 natural cushion diamonds typically cost $6,322 AUD to $17,778 AUD, with a median price of $11,167 AUD. There are currently 255 diamonds matching this specification available across retailers.

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

About 31% of these diamonds are available at multiple retailers, with an average price spread of 57%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct F SI1 Natural Cushion

Quick answer

As of October 2026, there are 255 natural cushion diamonds with F colour and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run $6,322 AUD to $17,778 AUD, with a median of $11,167 AUD. At least 60 retailers stock this exact specification, and 31% of the stones appear at more than one of them, with an average price spread of 57%. Half of all listings fall between $4,989 AUD and $8,855 AUD per carat. The same specification in lab grown form lists at a median of about $670 AUD per carat. Over the last 30 days the median price moved -2.6% and the number of listings moved +5.2%.

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

255

Lowest Price

$3,942 AUD

Highest Price

$35,428 AUD

Average Price

$11,703 AUD

Market Intelligence

Retailers Selling

Cross Retailer %

31.0%

Price Spread

57.4%

30-Day Price Trend

-2.6%

30-Day Supply Change

+5.2%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$4,735/ct

10th Percentile

$2,836

Median

$4,735

90th Percentile

$7,586

Score Distribution

632 diamonds scored across 4 quality tiers

Excellent

79 (12.5%)

Very Good

134 (21.2%)

Good

149 (23.6%)

Average

270 (42.7%)

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Consider Instead

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

F SI2SI2 inclusions are not visible without magnification

Save 26%

Lab-Grown F SI1Same specifications, lab-grown origin

Save 90%

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