I Colour

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

Total listings
1,497,090
Natural median (AUD)
$2,982/ct
Lab-grown median (AUD)
$1,882/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 1,497,090 active I colour listings across our retailer network. The typical natural I diamond trades around $2,982/ct while the lab-grown equivalent sits at $1,882/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 7.5% 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 732,481 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)
ROUNDnatural732,481$2,715/ct
OVALnatural144,764$3,513/ct
EMERALDnatural122,479$3,096/ct
PEARnatural116,610$3,037/ct
CUSHIONnatural73,557$4,183/ct
ROUNDlab grown67,792$2,081/ct
PRINCESSnatural56,573$3,143/ct
HEARTnatural40,638$2,928/ct
RADIANTnatural37,540$3,855/ct
MARQUISEnatural32,948$3,159/ct
ASSCHERnatural25,589$3,411/ct
PEARlab grown12,517$1,693/ct
OVALlab grown11,518$1,972/ct
EMERALDlab grown7,105$1,296/ct
CUSHIONlab grown3,511$1,405/ct
PRINCESSlab grown3,328$1,862/ct
RADIANTlab grown2,709$1,313/ct
MARQUISElab grown1,677$1,839/ct
HEARTlab grown1,235$1,735/ct
OTHERnatural1,224$4,483/ct
ASSCHERlab grown475$1,488/ct
TRILLIONnatural454$4,819/ct
OTHERlab grown245$647/ct
BAGUETTEnatural144$5,017/ct
SQ_RADIANTnatural62$3,624/ct
ROUNDunknown37$2,036/ct
BAGUETTElab grown36$781/ct
TRILLIONlab grown17$1,478/ct

Breakdown by Carat

CaratOriginListingsMedian (AUD)
0.5-0.99ctnatural479,130$2,248/ct
0.5-0.99ctlab grown26,235$2,266/ct
0.5-0.99ctunknown2$2,411/ct
1.0-1.49ctnatural304,928$3,879/ct
1.0-1.49ctlab grown15,828$1,872/ct
1.0-1.49ctunknown2$4,118/ct
1.5-1.99ctnatural168,176$5,924/ct
1.5-1.99ctlab grown23,496$1,692/ct
1.5-1.99ctunknown3$9,012/ct
2.0-2.99ctnatural102,467$9,299/ct
2.0-2.99ctlab grown22,466$1,837/ct
2.0-2.99ctunknown1$8,405/ct
3.0ct+natural50,611$16,985/ct
3.0ct+lab grown15,505$2,157/ct
3.0ct+unknown1$20,374/ct
under-0.5ctnatural279,751$1,943/ct
under-0.5ctlab grown8,637$2,297/ct
under-0.5ctunknown32$1,939/ct
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