How much does a 1.50 to 1.99ct G SI1 lab grown radiant diamond cost?

As of October 2026, 1.50 to 1.99ct G SI1 lab grown radiant diamonds typically cost $538 NZD to $3,811 NZD, with a median price of $1,318 NZD. There are currently 91 diamonds matching this specification available across retailers.

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

About 27% of these diamonds are available at multiple retailers, with an average price spread of 105%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.50 to 1.99ct G SI1 Lab Grown Radiant

Quick answer

As of October 2026, there are 91 lab grown radiant diamonds with G colour and SI1 clarity in the 1.50 to 1.99ct range available across retailers worldwide. Prices typically run $538 NZD to $3,811 NZD, with a median of $1,318 NZD. At least 37 retailers stock this exact specification, and 27% of the stones appear at more than one of them, with an average price spread of 105%. Half of all listings fall between $421 NZD and $1,231 NZD per carat. The same specification in natural form lists at a median of about $9,520 NZD per carat. Over the last 30 days the median price moved +5.6% and the number of listings moved +3.0%.

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. Radiant lab grown stones in the index: 474 USD per carat, -2.1% 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

Lowest Price

$275 NZD

Highest Price

$6,469 NZD

Average Price

$1,670 NZD

Market Intelligence

Retailers Selling

Cross Retailer %

26.8%

Price Spread

104.8%

30-Day Price Trend

+5.6%

30-Day Supply Change

+3.0%

Volatility (30d)

0.02

Price Range

Price per carat distribution across retailers

$436/ct

10th Percentile

$131

Median

$436

90th Percentile

$1,191

Score Distribution

158 diamonds scored across 4 quality tiers

Excellent

11 (7.0%)

Very Good

56 (35.4%)

Good

45 (28.5%)

Average

46 (29.1%)

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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