Vintage cushion cut ring

[faye]

I've heard that oldminer knows about this stuff, but anyone else's input is VERY welcome!

I have found a cusion cut diamond online at a very low price, but was advised recently that it is too shallow and will produce a "window effect." I feel dumb admitting this, but I don't really know what that means. My hunch is that it means you would be able to see through the diamond. Can someone please explain this to me? I know that diamond depth should be between 55-65%.

Also, if I could get another opinion on this potential purchase I would really appreciate it. Here are the specifics:

.95 carat jubilee cushion cut, 6.58x5.78x3.06mm, depth 52.9%, table 60%, crown 16.8%, pavilion 33.9%, girdle ex.thin to sl. thick semifaceted, good polish, fair symmetry, clarity I1, color G, no flourescence. Appraised at $5,130 five months ago by the EGL. Seller wants around half of that.

Thanks a lot!

 

[lacina]

Hi Faye,

If you offer the seller fifth of the appraisal he should take it and thank you for it! Perhaps one tenth would do...

In Diamond terminology this diamond will look like dogs rear end!
And EGL is relaxed on color and sometimes on clarity depending who is the rookie grading the diamond and witch lab is it from. If it is EGL Israel Forget it! So expect the diamond to be GIA H-J and possibly I2. Plus the stone is too shallow, never mind the window, you will get some brilliance because of the cushion cut but no fire when set. This stone is a great candidate for recuting, however It is not economically feasible to recut I clarity .98ct. You can find a very decent stone for $2600! Why bother?
Sorry to say this I hope everyone will agree with me.

George
GLE Gem Imports

 

[Richard Sherwood]

That's a lot of money for that stone. If you do a search on PriceScope above, you'll find 0.93-0.98 G/I1 modern round brilliant cuts ranging from $1900 to $2600. A modern cut stone is worth about twice as much as the average old mine cut.

You can do better. Don't buy it, unless you really like it and can buy it for a lot less.

A "window" is exactly what you think, by the way. It's created by a shallow depth, which causes a lot of light leakage in the center of the stone. It's usually a term used for colored stones with lower refractive indexes than diamond. In them, you can literally see through the center of the stone. You can't usually see through the center of a diamond, so the term is used figuratively.

Rich, Independent GG
Sarasota Gemological Laboratory

 

[Mara]

Ran a quick search on Pricescope and found the following:
1.0 carat, H, SI2 Cushion Cut
Depth: 62.4%
Table: 73%
GIA Cert
Good Polish, Good Symmetry
Faint Fluor
Culet: No
5.99-5.98x3.73
$2513 at Whiteflash.Com

Also check out diamondwholesale.cc , they usually have a great selection of older antique style stones for very reasonable pricing. I ran a quick search on them and found 35 Cushion Cut diamonds under $3000, the sizes range up to 1.30+ carats. Here is an example--sounds more reasonable in the dimensions..and its .35c bigger than your same priced example.

1.29 carat, H, I1 (somewhat similar to your example)
Depth: 67.6%
Table: 54% (sounds more realistic..don't know about Cushions)
EGL cert
Culet: Slight
Polish: Excellent, Symm: Good
Fluor: Slight
6.34*7*4.51
$2459

Noted that many of the older cut stones on sites have EGL certs, only found a few with GIA. So if you do end up with a stone with an EGL, it would not seem unusual for the older cuts.

I don't know if the above stones are considered a good cut for a Cushion, as the table seems high in the first one, but then again maybe that is realistic for a Cushion. But you will see that both prices are similar to what you are looking at paying for a shallower stone. Maybe the experts can weigh in on these above and any others you find. Don't give up and purchase the one you found just because it seems like a such a good deal. As you see there are many other stones in your price range that might be more quality stones and not give the glassy effect. I bet with a little research you could find a better cut cushion that will give much better light return and sparkle for the same $$.

Also if you have already been advised that your original stone is too shallow, why even consider it? In your search online you might note that there are many stones that are better than the I1 quality..you can probably get an SI1 or similar and an H/I/J color for the same price.

Hope this helps, best of luck!