I Colour

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

Total listings
1,247,457
Natural median (AUD)
$3,399/ct
Lab-grown median (AUD)
$2,142/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 1,247,457 active I colour listings across our retailer network. The typical natural I diamond trades around $3,399/ct while the lab-grown equivalent sits at $2,142/ct. Roughly a 37% gap that reflects the broader natural-vs-lab pricing gap, not a quality difference at this grade.

I commands a modest 8.3% 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 569,246 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)
ROUNDnatural569,246$3,135/ct
OVALnatural130,250$3,975/ct
EMERALDnatural100,198$3,631/ct
PEARnatural96,878$3,481/ct
ROUNDlab grown76,849$2,340/ct
CUSHIONnatural55,384$4,204/ct
PRINCESSnatural49,929$3,551/ct
HEARTnatural43,362$3,401/ct
RADIANTnatural27,693$3,838/ct
ASSCHERnatural23,893$3,620/ct
MARQUISEnatural21,669$3,444/ct
OVALlab grown14,175$2,306/ct
PEARlab grown13,870$1,912/ct
EMERALDlab grown7,793$1,361/ct
PRINCESSlab grown3,664$1,932/ct
CUSHIONlab grown3,398$1,544/ct
RADIANTlab grown2,989$1,432/ct
MARQUISElab grown1,839$2,030/ct
HEARTlab grown1,705$1,688/ct
OTHERnatural1,163$4,648/ct
ASSCHERlab grown888$1,359/ct
TRILLIONnatural452$5,383/ct
OTHERlab grown204$719/ct
BAGUETTEnatural135$5,588/ct
ROUNDunknown43$2,379/ct
BAGUETTElab grown37$784/ct
SQ_RADIANTnatural26$2,032/ct
TRILLIONlab grown18$854/ct

Breakdown by Carat

CaratOriginListingsMedian (AUD)
0.5-0.99ctnatural393,756$2,526/ct
0.5-0.99ctlab grown32,430$2,545/ct
0.5-0.99ctunknown2$3,417/ct
1.0-1.49ctnatural263,082$4,338/ct
1.0-1.49ctlab grown18,856$2,289/ct
1.0-1.49ctunknown6$5,011/ct
1.5-1.99ctnatural137,078$6,603/ct
1.5-1.99ctlab grown24,935$1,751/ct
1.5-1.99ctunknown4$9,075/ct
2.0-2.99ctnatural82,210$10,226/ct
2.0-2.99ctlab grown22,781$2,014/ct
2.0-2.99ctunknown1$10,084/ct
3.0ct+natural38,774$19,097/ct
3.0ct+lab grown15,921$1,932/ct
3.0ct+unknown1$24,716/ct
under-0.5ctnatural205,378$2,262/ct
under-0.5ctlab grown12,508$2,402/ct
under-0.5ctunknown34$2,143/ct
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