How much does a 5.00ct+ I SI1 natural oval diamond cost?

As of September 2026, 5.00ct+ I SI1 natural oval diamonds typically cost $66,852 SGD to $223,539 SGD, with a median price of $114,929 SGD. There are currently 112 diamonds matching this specification available across retailers.

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

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5.00ct+ I SI1 Natural Oval

Quick answer

As of September 2026, there are 112 natural oval diamonds with I colour and SI1 clarity in the 5.00ct+ range available across retailers worldwide. Prices typically run $66,852 SGD to $223,539 SGD, with a median of $114,929 SGD. At least 9 retailers stock this exact specification. Half of all listings fall between $19,583 SGD and $30,065 SGD per carat. The same specification in lab grown form lists at a median of about $605 SGD per carat.

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

Caratlytics Diamond Price Index, August 2026: natural diamonds at 2,184 USD per carat and lab-grown at 464 USD per carat, a natural to lab ratio of 4.7 to 1. Oval natural stones in the index: 2,380 USD per carat, -9.6% month on month. See the full index release

Figures come from live listings across more than 100 retailers and refresh daily. The index is a monthly release.

Last updated: September 2026

Available

112

Lowest Price

$43,892 SGD

Highest Price

$1,142,291 SGD

Average Price

$142,399 SGD

Market Intelligence

Retailers Selling

Price Spread

41.8%

Price Range

Price per carat distribution across retailers

$19,717/ct

10th Percentile

$11,431

Median

$19,717

90th Percentile

$26,497

Score Distribution

112 diamonds scored across 4 quality tiers

Excellent

6 (5.4%)

Very Good

31 (27.7%)

Good

32 (28.6%)

Average

43 (38.4%)

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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 33%

Lab-Grown I SI1Same specifications, lab-grown origin

Save 98%

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