carat vs. color  length*  width*

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

2 Ct Topaz (Round)


0.5 Ct Tourmaline (Oval)

7.85×7.85 mm 6.54×4.36 mm
actual size
Actual size of 2ct Topaz   Actual size of 0.5ct Tourmaline
Actual size is set for screen Change
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Blue 2ct Topaz on a ring
64 mm
Right finger image
Ring on a right finger
Violet 0.5ct Tourmaline 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 2ct Topaz Round (7.85×7.85mm, Blue) and 0.5ct Tourmaline Oval (6.54×4.36mm, Violet) 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?

For Topaz or Tourmaline check what Amazon has to offer. You'll usually find quite a selection from many different vendors. Worth a check. For other high quality gemstones (Rubies, Saphhires, Emeralds) and especially Diamonds, I highly recommend JamesAllen.

Face-up Size

All things being equal, Topaz will face-up smaller than Tourmaline for a given carat weight, because it has higher specific gravity (3.53 vs. 3.1 - this means it's "heavier" compared to Tourmaline of the same size). Face-up size also depends heavily on the 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.

2 Ct Topaz (Round) 0.5 Ct Tourmaline (Oval)
7.85×7.85 mm vs 6.54×4.36 mm
48.4 mm²   23.38 mm²
Face-up size outline
Face-up size outline
2ct Topaz Round (7.85×7.85mm)
0.5ct Tourmaline Oval (6.54×4.36mm)
Difference: 107% (25.02 mm²)
2ct Topaz Round (7.85×7.85mm) has approx. 107% more face-up area than 0.5ct Tourmaline Oval (6.54×4.36mm).

Popular comparisons:

Enter your screen size (diagonal)

My screen size is  inches

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.