carat vs. color  length*  width*

(or examine a single gem)
* size in mm (optional)

1 Ct Ruby (Emerald)


1 Ct Sapphire (Trillion)

6.39×4.73 mm 7.03×7.03 mm
actual size
Actual size of 1ct Ruby   Actual size of 1ct Sapphire
Actual size is set for screen Change
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Red 1ct Ruby on a ring
64 mm
Right finger image
Ring on a right finger
Blue 1ct Sapphire on a ring
Your settings
Skin tone
Ring diameter
16.9 mm
Ring width
3.0 mm
Finger length
64 mm
Ring diameter: 16.9 mm
Actual sizes of 1ct Ruby Emerald (6.39×4.73mm, Red) and 1ct Sapphire Trillion (7.03×7.03mm, Blue) as they would appear on a ring and finger. Adjust the ring and finger size to get an idea of how these gemstones would look on your finger.

Where to buy?

JamesAllen → high-quality gemstones (Rubies, Saphhires, Emeralds) and especially Diamonds, high-end jewelry and competitive prices. Highly recommended.
Amazon → usually offers a good selection from many different vendors. Worth a check.

Face-up Size

Ruby and Sapphire have the same specific gravity so their face-up size depends on the weight, shape and proportions of the cut. Face-up area is a measure of the size of the gem when viewed from above (as set in a ring). It tells you how big the gem is at the girdle plane.

1 Ct Ruby (Emerald) 1 Ct Sapphire (Trillion)
6.39×4.73 mm vs 7.03×7.03 mm
28.11 mm²   30.64 mm²
Face-up size outline
Face-up size outline
1ct Ruby Emerald (6.39×4.73mm)
1ct Sapphire Trillion (7.03×7.03mm)
Difference: 9% (2.53 mm²)
1ct Sapphire Trillion (7.03×7.03mm) has approx. 9% more face-up area than 1ct Ruby Emerald (6.39×4.73mm).

Popular comparisons:

Enter your screen size (diagonal)

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Actual size is currently adjusted to screen.

If your screen (phone, tablet, or monitor) is not in diagonal, then the actual size of a gem, ring and finger will not be shown correctly.