How much does a 1.00 to 1.49ct I SI1 natural cushion diamond cost?

As of October 2026, 1.00 to 1.49ct I SI1 natural cushion diamonds typically cost $1,675 CAD to $5,345 CAD, with a median price of $3,105 CAD. There are currently 566 diamonds matching this specification available across retailers.

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

About 35% of these diamonds are available at multiple retailers, with an average price spread of 60%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct I SI1 Natural Cushion

Quick answer

As of October 2026, there are 566 natural cushion diamonds with I color and SI1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run $1,675 CAD to $5,345 CAD, with a median of $3,105 CAD. At least 64 retailers stock this exact specification, and 35% of the stones appear at more than one of them, with an average price spread of 60%. Half of all listings fall between $2,267 CAD and $4,086 CAD per carat. The same specification in lab grown form lists at a median of about $804 CAD per carat. Over the last 30 days the median price moved -1.4% and the number of listings moved +10.7%.

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

566

Lowest Price

$1,155 CAD

Highest Price

$12,372 CAD

Average Price

$3,383 CAD

Market Intelligence

Retailers Selling

Cross Retailer %

35.1%

Price Spread

59.5%

30-Day Price Trend

-1.4%

30-Day Supply Change

+10.7%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$2,183/ct

10th Percentile

$1,318

Median

$2,183

90th Percentile

$3,779

Score Distribution

1.3K diamonds scored across 4 quality tiers

Excellent

236 (17.9%)

Very Good

317 (24.1%)

Good

348 (26.4%)

Average

415 (31.5%)

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Consider Instead

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

J SI1J colour is visually identical to I to the naked eye

Save 24%

Lab-Grown I SI1Same specifications, lab-grown origin

Save 76%

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