I Colour

Current pricing and availability for I colour diamonds across natural and lab-grown origins.

Total listings
1,962,292
Natural median (NZD)
$3,960/ct
Lab-grown median (NZD)
$1,644/ct

What I Colour Means for Buyers

I sits on the GIA colour scale that runs from D (colourless) at the top through to Z (faint yellow or brown). The higher up you go toward D, the rarer the stone and the steeper the price curve. But a huge number of buyers never tell the difference between two adjacent grades in a finished ring, especially once the diamond is mounted in yellow or rose gold.

Right now we're tracking 1,962,292 active I colour listings across our retailer network. The typical natural I diamond trades around $3,960/ct while the lab-grown equivalent sits at $1,644/ct. Roughly a 58% gap that reflects the broader natural-vs-lab pricing gap, not a quality difference at this grade.

I commands a modest 6.7% premium over the neighboring J grade. For buyers who prioritise face-up appearance over spec sheets, J delivers almost all of the visual quality for noticeably less. Pay for I only if you care about the grade showing on the cert.

I shows up most often in ROUND. About 1,018,395 listings at this moment. Followed by OVAL. Most of the supply clusters around the 0.5-0.99ct carat range, where demand is strongest and retailers keep the deepest inventory. If you're shopping an unusual shape or carat, expect thinner selection.

For most engagement-ring buyers, the practical sweet spot for colour is G or H. Colourless-appearing face-up, still a near-colourless grade on paper, and priced 30 to 50% below the D-E tier. If you're setting the stone in yellow or rose gold, you can comfortably go down to I or J without the stone looking warm. Save the money for a better cut grade; cut drives sparkle far more than the last step of colour.

Breakdown by Shape

ShapeOriginListingsMedian (NZD)
ROUNDnatural1,018,395$3,533/ct
OVALnatural181,091$4,921/ct
EMERALDnatural152,720$4,165/ct
PEARnatural143,697$4,139/ct
CUSHIONnatural92,664$5,420/ct
PRINCESSnatural75,106$4,160/ct
ROUNDlab grown55,039$1,686/ct
HEARTnatural52,829$4,018/ct
MARQUISEnatural48,757$4,254/ct
RADIANTnatural48,471$5,330/ct
ASSCHERnatural33,235$4,665/ct
PEARlab grown18,310$1,671/ct
OVALlab grown14,941$2,220/ct
EMERALDlab grown9,493$1,185/ct
CUSHIONlab grown3,911$1,173/ct
PRINCESSlab grown3,384$1,291/ct
RADIANTlab grown3,127$1,028/ct
OTHERnatural2,288$4,982/ct
MARQUISElab grown1,765$1,246/ct
HEARTlab grown1,175$1,346/ct
TRILLIONnatural758$5,299/ct
ASSCHERlab grown435$1,885/ct
OTHERlab grown317$964/ct
BAGUETTEnatural169$5,923/ct
SQ_RADIANTnatural142$4,470/ct
BAGUETTElab grown52$1,109/ct
ROUNDunknown33$2,470/ct
TRILLIONlab grown21$1,888/ct

Breakdown by Carat

CaratOriginListingsMedian (NZD)
0.5-0.99ctnatural617,127$2,863/ct
0.5-0.99ctlab grown20,000$1,553/ct
0.5-0.99ctunknown2$3,090/ct
1.0-1.49ctnatural395,923$5,128/ct
1.0-1.49ctlab grown13,243$1,737/ct
1.0-1.49ctunknown3$6,403/ct
1.5-1.99ctnatural223,220$7,699/ct
1.5-1.99ctlab grown31,418$1,735/ct
1.5-1.99ctunknown2$13,746/ct
2.0-2.99ctnatural134,284$12,023/ct
2.0-2.99ctlab grown30,869$2,350/ct
3.0ct+natural59,552$21,208/ct
3.0ct+lab grown13,603$821/ct
3.0ct+unknown1$26,880/ct
under-0.5ctnatural420,216$2,451/ct
under-0.5ctlab grown2,837$1,174/ct
under-0.5ctunknown28$2,335/ct
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