The 65/65 rule....

[MsGolightly]

Can somebody please explain what the 65/65 rule is?

 

[Hest88]

I think I've only heard Fred Cuellar use 65/65; most use the 60/60 rule.

The 60/60 rule is an outdated rule of thumb that said a diamond with a 60% table and 60% depth was ideal. It's since been proven to be wrong.

 

[pricescope]

I guess 65/65 is Fred's rule for fancies like Princess

 

[Rhino]

It is Fred's rule and has no basis in fact. It is "possible" to have a nice princess cut that is 65/65 but it is not likely as most are cut with shallow crowns with pavilions that do not compliment. His "rule" does not consider the most crucial element to brilliance and fire in diamonds and that is of the relationship between the crown/pavilion angles. I've analyzed dozens of princess cuts with seemingly GREAT table/total depth measurements only to turn up leakers. The equation that leaves out that relationship is nothing but an empty theory. It begs the question ... "WHERE'S THE BEEF?"

Rhino

 

[barry]

Painting by the "numbers" in Fancies
is a one-way street, i.e; certain numbers
will definitely indicate a poorly-cut,
low-light output, high light-leakage diamond
but not necessarily guarantee a high-octane
va-va-voom stone. My research over the past two years
with Princess-Cuts indicates that there are several
"numbers" combinations outside of what is currently considered to be chart "ideal" that will result
in a beautiful diamond. That is why I do not
show Megascope data for Princesses
on my website but instead display visual
information in the form of the
Digital Photos, BrillianceScope, and ImageScope to demonstrate light output and light leakage.

Barry
www.superbcert.com