Color and Weight Premium?

[gemnewbie]

1. Can someone please tell me, if all other things being exactly equal in a well-cut stone,
how much of a primium will a 3.05 ct J-VS2 diamond sell for, compared to a K-VS2?

2. I know the cost per ct. goes up at certain weight elevels. Is there a per ct premium for a 3.05 stone, compared to one that''s slightly under, such as 2.85? If so, what is the per ct premium increase in this situation at the 3.00 level?

 

[FB.]

Each stone would be individually assessed.

Price between two apparently identical stones could vary depending on:

Who is selling the stone.
Which lab (if any) graded the stone.
The lab-awarded cut grade (if applicable).
Any nasty cutters tricks employed in the cutting of the stone.
Whether the colour is a "good" J (nearer to I), an "average" J, or a "low" J (nearer to L).
The detailed proportions - even a few tenths of a degree on the crown and pavilion angles can make a huge difference to sparkle and price will reflect that.
Whether it was a "good" VS2 (closer to VS1), an "average" VS2, or a "bad" VS2 (closer to SI1). A bad VS2 might not be completely eye clean. Even the types of inclusions could affect the price - a single large feather in a low VS2 might pose a structural risk.
Presence and/or intensity of fluorescence.

Probably not what you wanted to hear.

 

[FB.]

3.06ct compared to 3.00ct would cost 3.06/3.00 = 1.02 => 2% more.
Being just below a carat mark gives a better discount than simply the difference in weight.

J costs about 10% more than K.