How much does a 5.00ct+ G SI1 natural round diamond cost?

As of October 2026, 5.00ct+ G SI1 natural round diamonds typically cost $133,413 AUD to $298,712 AUD, with a median price of $170,312 AUD. There are currently 58 diamonds matching this specification available across retailers.

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

About 44% of these diamonds are available at multiple retailers, with an average price spread of 34%. A comparison tool like Carat Hunter lets you see all the prices side by side.

5.00ct+ G SI1 Natural Round

Quick answer

As of October 2026, there are 58 natural round diamonds with G colour and SI1 clarity in the 5.00ct+ range available across retailers worldwide. Prices typically run $133,413 AUD to $298,712 AUD, with a median of $170,312 AUD. At least 7 retailers stock this exact specification, and 44% of the stones appear at more than one of them, with an average price spread of 34%. Half of all listings fall between $39,531 AUD and $55,756 AUD per carat. The same specification in lab grown form lists at a median of about $415 AUD per carat. Over the last 30 days the median price moved -4.8% and the number of listings moved -13.3%.

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. Round natural stones in the index: 2,248 USD per carat, +7.6% 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

$83,753 AUD

Highest Price

$670,031 AUD

Average Price

$193,272 AUD

Market Intelligence

Retailers Selling

Cross Retailer %

43.8%

Price Spread

34.4%

30-Day Price Trend

-4.8%

30-Day Supply Change

-13.3%

Volatility (30d)

0.04

Price Range

Price per carat distribution across retailers

$33,147/ct

10th Percentile

$26,344

Median

$33,147

90th Percentile

$46,292

Score Distribution

163 diamonds scored across 4 quality tiers

Excellent

19 (11.7%)

Very Good

34 (20.9%)

Good

36 (22.1%)

Average

74 (45.4%)

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Consider Instead

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

H SI1H colour is visually identical to G to the naked eye

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Lab-Grown G SI1Same specifications, lab-grown origin

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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