carat vs. color  length*  width*

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

1 Ct Kyanite (Oval)


1 Ct Tanzanite (Oval)

7.77×5.18 mm 8.07×5.38 mm
actual size
Actual size of 1ct Kyanite   Actual size of 1ct Tanzanite
Actual size is set for screen Change
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Blue 1ct Kyanite on a ring
64 mm
Right finger image
Ring on a right finger
Blue 1ct Tanzanite 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 Kyanite Oval (7.77×5.18mm, Blue) and 1ct Tanzanite Oval (8.07×5.38mm, 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?

For Kyanite or Tanzanite 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, Kyanite will face-up smaller than Tanzanite for a given carat weight, because it has higher specific gravity (3.68 vs. 3.3 - this means it's "heavier" compared to Tanzanite 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.

1 Ct Kyanite (Oval) 1 Ct Tanzanite (Oval)
7.77×5.18 mm vs 8.07×5.38 mm
33 mm²   35.6 mm²
Face-up size outline
Face-up size outline
1ct Kyanite Oval (7.77×5.18mm)
1ct Tanzanite Oval (8.07×5.38mm)
Difference: 8% (2.6 mm²)
1ct Tanzanite Oval (8.07×5.38mm) has approx. 8% more face-up area than 1ct Kyanite Oval (7.77×5.18mm).

Popular comparisons:

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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.