I Colour

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

Total listings
1,962,292
Natural median (AUD)
$3,166/ct
Lab-grown median (AUD)
$1,314/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 $3,166/ct while the lab-grown equivalent sits at $1,314/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 (AUD)
ROUNDnatural1,018,395$2,824/ct
OVALnatural181,091$3,934/ct
EMERALDnatural152,720$3,330/ct
PEARnatural143,697$3,309/ct
CUSHIONnatural92,664$4,333/ct
PRINCESSnatural75,106$3,326/ct
ROUNDlab grown55,039$1,348/ct
HEARTnatural52,829$3,212/ct
MARQUISEnatural48,757$3,401/ct
RADIANTnatural48,471$4,261/ct
ASSCHERnatural33,235$3,729/ct
PEARlab grown18,310$1,336/ct
OVALlab grown14,941$1,775/ct
EMERALDlab grown9,493$948/ct
CUSHIONlab grown3,911$938/ct
PRINCESSlab grown3,384$1,032/ct
RADIANTlab grown3,127$822/ct
OTHERnatural2,288$3,983/ct
MARQUISElab grown1,765$996/ct
HEARTlab grown1,175$1,076/ct
TRILLIONnatural758$4,236/ct
ASSCHERlab grown435$1,507/ct
OTHERlab grown317$771/ct
BAGUETTEnatural169$4,735/ct
SQ_RADIANTnatural142$3,573/ct
BAGUETTElab grown52$886/ct
ROUNDunknown33$1,975/ct
TRILLIONlab grown21$1,509/ct

Breakdown by Carat

CaratOriginListingsMedian (AUD)
0.5-0.99ctnatural617,127$2,288/ct
0.5-0.99ctlab grown20,000$1,242/ct
0.5-0.99ctunknown2$2,470/ct
1.0-1.49ctnatural395,923$4,099/ct
1.0-1.49ctlab grown13,243$1,389/ct
1.0-1.49ctunknown3$5,119/ct
1.5-1.99ctnatural223,220$6,155/ct
1.5-1.99ctlab grown31,418$1,387/ct
1.5-1.99ctunknown2$10,989/ct
2.0-2.99ctnatural134,284$9,612/ct
2.0-2.99ctlab grown30,869$1,879/ct
3.0ct+natural59,552$16,954/ct
3.0ct+lab grown13,603$656/ct
3.0ct+unknown1$21,489/ct
under-0.5ctnatural420,216$1,960/ct
under-0.5ctlab grown2,837$938/ct
under-0.5ctunknown28$1,867/ct
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