How big is a 1 carat zircon?

By HeyGema™ · Updated

In short

A 1 carat round zircon measures about 5.9 mm across (0.23 inches), 9% narrower than a 1 carat diamond (6.5 mm). An oval of the same weight is 7.3 x 5.0 mm and an emerald cut 6.4 x 4.5 mm.

Carat to mm calculator

About 5.9 x 5.9 mm

An estimate for a well-cut stone. A deep or shallow cut faces up smaller or bigger.

Round
5.9 mm
Oval
7.3 x 5.0 mm
Cushion
5.1 x 5.1 mm
Princess
5.0 x 5.0 mm
Emerald cut
6.4 x 4.5 mm
Asscher
5.0 x 5.0 mm
Radiant
5.9 x 4.5 mm
Pear
7.7 x 5.0 mm
Marquise
9.5 x 4.7 mm
Heart
5.9 x 5.9 mm
Trillion
6.4 x 6.4 mm
Baguette
7.3 x 3.6 mm
= 2 mm in every picture above
A 1 carat zircon in 12 shapes, drawn to one scale.

1 carat zircon size by shape

Face-up measurements of a well-cut 1 carat zircon. Zircon is denser than diamond (4.69 against 3.52), so it packs more weight into less space and faces up 9% narrower for the same weight.

Round
Length x width: 5.9 mm
In inches: 0.23 in
Oval
Length x width: 7.3 x 5.0 mm
In inches: 0.29 x 0.20 in
Cushion
Length x width: 5.1 x 5.1 mm
In inches: 0.20 x 0.20 in
Princess
Length x width: 5.0 x 5.0 mm
In inches: 0.20 x 0.20 in
Emerald cut
Length x width: 6.4 x 4.5 mm
In inches: 0.25 x 0.18 in
Asscher
Length x width: 5.0 x 5.0 mm
In inches: 0.20 x 0.20 in
Radiant
Length x width: 5.9 x 4.5 mm
In inches: 0.23 x 0.18 in
Pear
Length x width: 7.7 x 5.0 mm
In inches: 0.30 x 0.20 in
Marquise
Length x width: 9.5 x 4.7 mm
In inches: 0.37 x 0.19 in
Heart
Length x width: 5.9 x 5.9 mm
In inches: 0.23 x 0.23 in
Trillion
Length x width: 6.4 x 6.4 mm
In inches: 0.25 x 0.25 in
Baguette
Length x width: 7.3 x 3.6 mm
In inches: 0.29 x 0.14 in

1 carat zircon against other gems

Diamond
Round, 1 carat: 6.5 mm
Moissanite
Round, 1 carat: 6.6 mm
Sapphire
Round, 1 carat: 6.2 mm
Ruby
Round, 1 carat: 6.2 mm
Emerald
Round, 1 carat: 7.0 mm
Aquamarine
Round, 1 carat: 7.0 mm
Morganite
Round, 1 carat: 7.0 mm
Tanzanite
Round, 1 carat: 6.6 mm
Zircon (this page)
Round, 1 carat: 5.9 mm

1 carat zircon on a finger

5.9 mm
5.9 mm stone on a 16.5 mm finger: it covers 36% of the widthA round 1 carat zircon on a size 6 finger.
4
Finger width: 14.9 mm
Round covers: 39%
Oval covers: 34%
5
Finger width: 15.7 mm
Round covers: 37%
Oval covers: 32%
6
Finger width: 16.5 mm
Round covers: 36%
Oval covers: 30%
7
Finger width: 17.3 mm
Round covers: 34%
Oval covers: 29%
8
Finger width: 18.1 mm
Round covers: 32%
Oval covers: 28%
9
Finger width: 18.9 mm
Round covers: 31%
Oval covers: 26%

Zircon at nearby weights

0.5 carat zircon
Round diameter: 4.7 mm
1 ct (this page)
Round diameter: 5.9 mm
1.5 carat zircon
Round diameter: 6.7 mm

Questions

A round 1 carat zircon is about 5.9 mm across. Other shapes are longer than they are wide: an oval is 7.3 x 5.0 mm.
No. A round 1 carat zircon is 9% narrower than a 1 carat diamond (6.5 mm).
0.20 grams. A carat is 200 milligrams for every gem.
A round 1 carat zircon covers 36% of the width of a size 6 finger. Compare it with a ring you have tried on in the finger chart above.

More size charts