How much does a 0.75 to 0.99ct I SI1 natural heart diamond cost?

As of October 2026, 0.75 to 0.99ct I SI1 natural heart diamonds typically cost $1,465 NZD to $4,418 NZD, with a median price of $2,199 NZD. There are currently 179 diamonds matching this specification available across retailers.

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

About 36% of these diamonds are available at multiple retailers, with an average price spread of 90%. A comparison tool like Carat Hunter lets you see all the prices side by side.

0.75 to 0.99ct I SI1 Natural Heart

Quick answer

As of October 2026, there are 179 natural heart diamonds with I colour and SI1 clarity in the 0.75 to 0.99ct range available across retailers worldwide. Prices typically run $1,465 NZD to $4,418 NZD, with a median of $2,199 NZD. At least 60 retailers stock this exact specification, and 36% of the stones appear at more than one of them, with an average price spread of 90%. Half of all listings fall between $2,258 NZD and $4,870 NZD per carat. Over the last 30 days the median price moved -2.1% and the number of listings moved +10.8%.

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. Heart natural stones in the index: 2,374 USD per carat, +9.8% 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

179

Lowest Price

$996 NZD

Highest Price

$10,999 NZD

Average Price

$2,629 NZD

Market Intelligence

Retailers Selling

Cross Retailer %

36.4%

Price Spread

89.6%

30-Day Price Trend

-2.1%

30-Day Supply Change

+10.8%

Volatility (30d)

0.01

Price Range

Price per carat distribution across retailers

$1,637/ct

10th Percentile

$1,077

Median

$1,637

90th Percentile

$3,458

Score Distribution

474 diamonds scored across 4 quality tiers

Excellent

79 (16.7%)

Very Good

68 (14.3%)

Good

158 (33.3%)

Average

169 (35.7%)

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

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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