Looking at a Diamond!?

[Jomiy]

Hello all Pricescopers,

I have been doing exhaustive research on diamonds after deciding to purchase an engagement ring. This site and many others have been helpful. I love the objective measures of numbers and dimensions (I''m an engineer), but I still want the best looking diamond! However, this is very subjective....

So the other day I was at a local chain, I told the sales person to bring out a $5k and a $10k diamond with similar color grades. My gf and I were looking at each one and I could barely see the difference (One had more dark areas than the other). We were in an office looking at them on a white piece of paper with a small UV looking light and we didn''t look at them in daylight.

So to my question, what qualities am I supposed to be noticing for when looking at a diamond? Are there supposed to be less black areas (assuming my head isn''t blocking light from entering)? If 2 diamonds have the same amount of black areas, but one has more "rainbowy" reflections is that one better? My gf and I were looking at the 2 videos posted by Gary in another post, and I can''t see any difference between 1,3,4 (2 looks VERY different. I don''t see distinct "arrows")

I''m planning on comparing a Hearts on Fire diamond to a GIA Ex/AGS Ideal cut to see if I can even view a difference. However, it''d be helpful if I knew what to look for...

Thanks!

 

[Hest88]

Jomify, when you compare the HoF, ask them to show you a diamond they think is far from ideal too.

Also, check out Good Gold Gold''s video tutorials:
http://www.goodoldgold.com/Diamond_Videos/

 

[FB.]

What to look for?

Firstly, get an idea of the angles and proportions.
Most people would agree that something like this is very likely to make the top grade:

Crown angle: 34.0-35.0 degrees.
Pavilion angle: 40.6-41.0 degrees.
Table: 55-57%
Depth: less than 62%
Girdle: thin to medium, medium, or medium-slightly thick.
Very good to excellent polish and symmetry.

The very best stones are likely to be in the middle of the proportion sets; 34.5crown angle, 40.8 pavilion angle, 56 table, medium girdle.

But how to judge a not-so-good stone in one simple way?
Hold the stone up to the light and look through both the top and bottom. A well-cut stone should have none - or only a few - tiny pinpoints of light coming through from behind it.

 

[FB.]

OK, here''s a few pictures that I just doctored of a shallow stone that will show "obstruction", a deep stone that will show "leakage - steep/deep" and a super-ideal cut:

 

[Jomiy]

Thanks for the quick reply guys.

I''ll be sure to watch the GoodoldGold videos when I get home from work. I''ve seen a few other video tutorials online but they don''t tell me WHAT to look for. Only to look at it in various lighting, look at all angles, watch out for nailheads or fisheyes, etc.

Yes I''m excited to see a HoF, an "ideal/excellent" cut, and one dog all side by side. If I can''t tell the difference (or my gf) for that matter then it''ll be interesting...