How big is a 1 carat iolite?

By HeyGema™ · Updated

In short

A 1 carat round iolite measures about 7.1 mm across (0.28 inches), 10% wider than a 1 carat diamond (6.5 mm). An oval of the same weight is 8.8 x 6.1 mm and an emerald cut 7.7 x 5.5 mm.

Carat to mm calculator

About 7.1 x 7.1 mm

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

Round
7.1 mm
Oval
8.8 x 6.1 mm
Cushion
6.2 x 6.2 mm
Princess
6.1 x 6.1 mm
Emerald cut
7.7 x 5.5 mm
Asscher
6.1 x 6.1 mm
Radiant
7.2 x 5.5 mm
Pear
9.4 x 6.1 mm
Marquise
11.5 x 5.7 mm
Heart
7.2 x 7.2 mm
Trillion
7.7 x 7.7 mm
Baguette
8.8 x 4.4 mm
= 2 mm in every picture above
A 1 carat iolite in 12 shapes, drawn to one scale.

1 carat iolite size by shape

Face-up measurements of a well-cut 1 carat iolite. Iolite is lighter than diamond (2.61 against 3.52), so the same weight gives a bigger stone, 10% wider across.

Round
Length x width: 7.1 mm
In inches: 0.28 in
Oval
Length x width: 8.8 x 6.1 mm
In inches: 0.35 x 0.24 in
Cushion
Length x width: 6.2 x 6.2 mm
In inches: 0.24 x 0.24 in
Princess
Length x width: 6.1 x 6.1 mm
In inches: 0.24 x 0.24 in
Emerald cut
Length x width: 7.7 x 5.5 mm
In inches: 0.30 x 0.22 in
Asscher
Length x width: 6.1 x 6.1 mm
In inches: 0.24 x 0.24 in
Radiant
Length x width: 7.2 x 5.5 mm
In inches: 0.28 x 0.22 in
Pear
Length x width: 9.4 x 6.1 mm
In inches: 0.37 x 0.24 in
Marquise
Length x width: 11.5 x 5.7 mm
In inches: 0.45 x 0.23 in
Heart
Length x width: 7.2 x 7.2 mm
In inches: 0.28 x 0.28 in
Trillion
Length x width: 7.7 x 7.7 mm
In inches: 0.30 x 0.30 in
Baguette
Length x width: 8.8 x 4.4 mm
In inches: 0.35 x 0.17 in

1 carat iolite 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
Iolite (this page)
Round, 1 carat: 7.1 mm

1 carat iolite on a finger

7.1 mm
7.1 mm stone on a 16.5 mm finger: it covers 43% of the widthA round 1 carat iolite on a size 6 finger.
4
Finger width: 14.9 mm
Round covers: 48%
Oval covers: 41%
5
Finger width: 15.7 mm
Round covers: 45%
Oval covers: 39%
6
Finger width: 16.5 mm
Round covers: 43%
Oval covers: 37%
7
Finger width: 17.3 mm
Round covers: 41%
Oval covers: 35%
8
Finger width: 18.1 mm
Round covers: 39%
Oval covers: 34%
9
Finger width: 18.9 mm
Round covers: 38%
Oval covers: 32%

Iolite at nearby weights

0.5 carat iolite
Round diameter: 5.7 mm
1 ct (this page)
Round diameter: 7.1 mm
1.5 carat iolite
Round diameter: 8.2 mm

Questions

A round 1 carat iolite is about 7.1 mm across. Other shapes are longer than they are wide: an oval is 8.8 x 6.1 mm.
Yes. A round 1 carat iolite is 10% wider than a 1 carat diamond (6.5 mm).
0.20 grams. A carat is 200 milligrams for every gem.
A round 1 carat iolite covers 43% 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