How much does a 1.00 to 1.49ct I SI2 natural cushion diamond cost?

As of September 2026, 1.00 to 1.49ct I SI2 natural cushion diamonds typically cost HK$8,983 HKD to HK$27,594 HKD, with a median price of HK$16,145 HKD. There are currently 771 diamonds matching this specification available across retailers.

Where can I find the best price on a I SI2 cushion diamond?

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1.00 to 1.49ct I SI2 Natural Cushion

Quick answer

As of September 2026, there are 771 natural cushion diamonds with I colour and SI2 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run HK$8,983 HKD to HK$27,594 HKD, with a median of HK$16,145 HKD. At least 48 retailers stock this exact specification. Half of all listings fall between HK$12,296 HKD and HK$22,062 HKD per carat. The same specification in lab grown form lists at a median of about HK$9,575 HKD per carat.

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

Caratlytics Diamond Price Index, August 2026: natural diamonds at 2,184 USD per carat and lab-grown at 464 USD per carat, a natural to lab ratio of 4.7 to 1. Cushion natural stones in the index: 2,792 USD per carat, +1.1% month on month. See the full index release

Figures come from live listings across more than 100 retailers and refresh daily. The index is a monthly release.

Last updated: September 2026

Available

771

Lowest Price

HK$5,531 HKD

Highest Price

HK$60,821 HKD

Average Price

HK$17,438 HKD

Market Intelligence

Retailers Selling

Price Spread

57.5%

Price Range

Price per carat distribution across retailers

$2,167/ct

10th Percentile

$1,242

Median

$2,167

90th Percentile

$3,496

Score Distribution

771 diamonds scored across 4 quality tiers

Excellent

65 (8.4%)

Very Good

180 (23.3%)

Good

265 (34.4%)

Average

261 (33.9%)

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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