For starters, you might like a cute little bird's eye view on jewelry-related forums on Richard Wise's Blog
Rating the Gem/Jewelry Forums
There are a few E-ring related forums: the largest is probably Pricescope... They do not make a secret of commercial interest: there are subscribing sellers that understandably act as insiders to some extent. If you ever wanted to know all there is to know and then some about cut branding, including proprietary models and the cut grading by the major labs (mostly AGS and GIA). That's the place. I definitely enjoyed the topic for the technical part, but IMO, it should remain a personal decision what matters and what doesn't. For that, a non-commercial source of information is always better. But again, someone has to pay the piper... most of the time.
Second the nudge to
Gemology-Online; it feels great and I definitely enjoy that company as well
It would probably help to open the question, as there isn't allot of previous talk there about diamond purchase in particular although expert advice isn't lacking with so many professionals posting arcane gemology stuff!
On the matter of diamonds alone, I have two favorite pieces of literature online:
One is a bit of with about the logic of diamond grading by Richard Hughes - it would be black humor if the topic itself wouldn't be so light
Devil?s Advocate: The Naked Eye
The other is Tolkowsky's original paper on cut:
LINK to Jasper Pausen's edited issue
The follow up towards the current parametrization nightmare around the round brilliant cut is quite mind boggling!
Gia and
OctoNus (a technology developer for diamond cutting) carry a load of that online, but again, if it isn't an end in itself... it is much to much to go through for any practical purpose, IMO... after I had (mostly).
Basically, enjoy the ride!
It never ceases to amaze me what a bewildering maze of intimidating, confusing and exhausting information mire could possibly be built around such quintessentially simple objects!
