How big is a 4 carat zircon?

By HeyGema™ · Updated

In short

A 4 carat round zircon measures about 9.3 mm across (0.37 inches), 9% narrower than a 4 carat diamond (10.2 mm). An oval of the same weight is 11.5 x 7.9 mm and an emerald cut 10.1 x 7.2 mm.

Carat to mm calculator

About 9.3 x 9.3 mm

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

Round
9.3 mm
Oval
11.5 x 7.9 mm
Cushion
8.1 x 8.1 mm
Princess
7.9 x 7.9 mm
Emerald cut
10.1 x 7.2 mm
Asscher
7.9 x 7.9 mm
Radiant
9.4 x 7.2 mm
Pear
12.3 x 7.9 mm
Marquise
15.0 x 7.5 mm
Heart
9.4 x 9.4 mm
Trillion
10.1 x 10.1 mm
Baguette
11.5 x 5.8 mm
= 5 mm in every picture above
A 4 carat zircon in 12 shapes, drawn to one scale.

4 carat zircon size by shape

Face-up measurements of a well-cut 4 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: 9.3 mm
In inches: 0.37 in
Oval
Length x width: 11.5 x 7.9 mm
In inches: 0.45 x 0.31 in
Cushion
Length x width: 8.1 x 8.1 mm
In inches: 0.32 x 0.32 in
Princess
Length x width: 7.9 x 7.9 mm
In inches: 0.31 x 0.31 in
Emerald cut
Length x width: 10.1 x 7.2 mm
In inches: 0.40 x 0.28 in
Asscher
Length x width: 7.9 x 7.9 mm
In inches: 0.31 x 0.31 in
Radiant
Length x width: 9.4 x 7.2 mm
In inches: 0.37 x 0.28 in
Pear
Length x width: 12.3 x 7.9 mm
In inches: 0.48 x 0.31 in
Marquise
Length x width: 15.0 x 7.5 mm
In inches: 0.59 x 0.30 in
Heart
Length x width: 9.4 x 9.4 mm
In inches: 0.37 x 0.37 in
Trillion
Length x width: 10.1 x 10.1 mm
In inches: 0.40 x 0.40 in
Baguette
Length x width: 11.5 x 5.8 mm
In inches: 0.45 x 0.23 in

4 carat zircon against other gems

Diamond
Round, 4 carat: 10.2 mm
Moissanite
Round, 4 carat: 10.5 mm
Sapphire
Round, 4 carat: 9.8 mm
Ruby
Round, 4 carat: 9.8 mm
Emerald
Round, 4 carat: 11.2 mm
Aquamarine
Round, 4 carat: 11.2 mm
Morganite
Round, 4 carat: 11.1 mm
Tanzanite
Round, 4 carat: 10.4 mm
Zircon (this page)
Round, 4 carat: 9.3 mm

4 carat zircon on a finger

9.3 mm
9.3 mm stone on a 16.5 mm finger: it covers 56% of the widthA round 4 carat zircon on a size 6 finger.
4
Finger width: 14.9 mm
Round covers: 63%
Oval covers: 53%
5
Finger width: 15.7 mm
Round covers: 59%
Oval covers: 51%
6
Finger width: 16.5 mm
Round covers: 56%
Oval covers: 48%
7
Finger width: 17.3 mm
Round covers: 54%
Oval covers: 46%
8
Finger width: 18.1 mm
Round covers: 51%
Oval covers: 44%
9
Finger width: 18.9 mm
Round covers: 49%
Oval covers: 42%

Zircon at nearby weights

3 carat zircon
Round diameter: 8.5 mm
4 ct (this page)
Round diameter: 9.3 mm
5 carat zircon
Round diameter: 10.0 mm

Questions

A round 4 carat zircon is about 9.3 mm across. Other shapes are longer than they are wide: an oval is 11.5 x 7.9 mm.
No. A round 4 carat zircon is 9% narrower than a 4 carat diamond (10.2 mm).
0.80 grams. A carat is 200 milligrams for every gem.
A round 4 carat zircon covers 56% 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