How much does a 1.50 to 1.99ct K SI1 natural heart diamond cost?

As of November 6, 2026, 1.50 to 1.99ct K SI1 natural heart diamonds typically cost $3,364 AUD to $8,595 AUD, with a median price of $4,890 AUD. There are currently 145 diamonds matching this specification available across retailers.

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

About 46% of these diamonds are available at multiple retailers, with an average price spread of 44%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct K SI1 Natural Heart

Quick answer

As of November 6, 2026, there are 145 natural heart diamonds with K colour and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run $3,364 AUD to $8,595 AUD, with a median of $4,890 AUD. Half of all listings fall between $2,546 AUD and $3,891 AUD per carat. Over the last 30 days the median price moved +0.6% and the number of listings moved +11.2%.

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

Caratlytics Diamond Price Index, October 2026: natural diamonds at 2,202 USD per carat and lab-grown at 462 USD per carat, a natural to lab ratio of 4.8 to 1. Heart natural stones in the index: 2,289 USD per carat, -3.7% month on month. See the full index release

Figures come from current listings across more than 125 retailers. The index is a monthly release.

Last updated: November 6, 2026

Available

145

Lowest Price

$2,199 AUD

Highest Price

$20,515 AUD

Average Price

$5,541 AUD

Market Intelligence

Cross Retailer %

45.5%

Price Spread

44.2%

30-Day Price Trend

+0.6%

30-Day Supply Change

+11.2%

Volatility (30d)

0.00

Price Range

Price per carat distribution across retailers

$2,093/ct

10th Percentile

$1,522

Median

$2,093

90th Percentile

$3,858

Score Distribution

145 diamonds scored across 4 quality tiers

Excellent

45 (31.0%)

Very Good

29 (20.0%)

Good

31 (21.4%)

Average

40 (27.6%)

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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