Newbie_Question about colored gems

[Sassy*Stone*Lover]

Hey gals, and guys! I''m super new at buying jewels and I was wanting to know what a stone size of 7.0/7.0 was in relation to carat size? Can anyone help me out?

Thanks so much!

 

[ma re]

It's generally about 2 cts, but it depends on a lot of factors - cutting style and proportions mostly. A shallow stone (with what is called a "window effect") will be larger and the one showing extinction of light will be smaller as it's cut deeper. The way each of the stone's main parts (crown and pavillion) is cut also plays a role, and so does specific gravity i.e. density of the material in question. For example, a sapphire or ruby will be a bit smaller than an amethyst or an aquamarine of the same cut and weight, cause it's denser.

 

[FrekeChild]

A 7mm stone will weigh different amounts depending on the stone species because they all have different densities. My 1.2ct spinel is 6.5mm--about the same size as a 1ct diamond. I believe sapphire is even denser than spinel, and so you''d need a heavier stone to achieve the same mm size. Does that make sense?

 

[FrekeChild]

Damn too late to edit. I have a spinel that is 7mm and is 1.6cts....

 

[Brown.Eyed.Girl]

Date: 3/5/2009 2:45:32 AM
Author:Sassy*Stone*Lover
Hey gals, and guys! I''m super new at buying jewels and I was wanting to know what a stone size of 7.0/7.0 was in relation to carat size? Can anyone help me out?


Thanks so much!

What shape are you thinking?

I have a 7x7 garnet cushion that 1.98 ct.

 

[chrono]

Generally, 7 x 7 mm is around 2 carats. There is a possibility of it being different due to:
1. Cut: if shallow, it''ll be less ct. If deep or an asscher cut, it''ll be more ct.
2. Density: aquamarines will be less ct, a sapphire will be more ct.