diameter size

[mischa]

I have read that a 1.0 ct diamond should be 6.5 mm

What about a 6.3 mm diameter? What does a smaller diameter mean?

Here are the spec:
-1.00 carat, round brilliant, VS1, I
-Table=55%
-Depth=62.2%
-Crown=15.6%
-Girdle=1.4-1.9%
-Pavilion Depth=42.8%
-Crown angle=35.2
-Pavilion angle=40.8
-Cutlet=none
-Fluorescence=median blue
-Polish=excellent
-Symmetry=excellent

Thank you

 

[verticalhorizon]

A smaller diameter usually means a diamond with a deeper pavillion or thicker girdle.

Your example scored a 2 on the HCA, which is still very good. You'll have to see it to really make a decision on it, but it should mean a very good value.

 

[oldminer]

6.4 is about right....It does vary a bit. The girdle thickness alters the diameter without changing the angles.

 

[phoenixgirl]

Well, there will be some variation in diameter, so 6.5 is a guideline more than anything.

However, a small diameter usually means that the stone has a greater total depth percentage and/or girdle thickness than the most ideal cut stones. For the consumer, this may mean that the stone is not as well cut (although yours seems to fall within acceptable parameters), and it always means that the stone will look smaller (although maybe only slightly) than a stone with the average diameter for that weight.

A stone like this one with a 66% depth is going to look a lot smaller (it only has a 6.0 diameter!). Your stone should be fine and the difference minimal, but I guess one thing to consider is whether or not you're paying for that magic "one carat" benchmark when your stone may only look like a 0.93 or 0.94 or so.

Here's a smaller H VS1 with a bigger diameter for example.

 

[verticalhorizon]

Yes, of course Dave is right. 6.4mm isn't so far off the mark that it should be discarded.

This might be too geeky, but here's a pretty good study done on various vendors and their average spread per carat.

Who's diamonds look biggest?