Round Stones, "Points" and Measurements

[Appreciative-of-expertise]

Hi, all!

I need some guidance regarding finding a chart or information that will associate the size of a round stone (Diameter) to the size in carats. I am searching for round stones for a channel setting that are to be: 4mm, 3.5mm and 3mm across the table. What does this, in general, associate with carat size?

Thanks!

 

[Patty]

I tried to post a conversion chart here but couldn't get it to post. A 4mm stone is about 1/4 ct. or 23-25 points. A 3 1/2mm diamond would be about 16 or 17 points and a 3mm stone is about 10 or 11 points.

 

[pyramid]

Just came across this on the Zales site.


Here is the link

http://www.zales.com/productknowledge.aspx?pid=38#Diamond%20Science

 

[Superidealist]

To find the approximate carat weight of a well-cut diamond given its diameter, use the following formula:

Carat weight = (Diameter / 6.5)^3

 

[Mara]

I recommend WhiteFlash's ACA Melee for your smaller stones...they carry them as small as .01c

For the larger 4mm ones you would probably need to pay a little more since they AGS cert anything over .20c which means more $$....but for the .16 (I think they carry .15) and .10 you would just buy using their melee pricing.

 

[Giangi]

You are looking at aboout respectively 0.23ct (4mm), 0.15ct(3.5mm) and 0.10ct (3mm). I too would suggest ACA melee. They seem to be marvelous.