How to evaluate tiny diamonds?

[antigoon]

My fiancee is looking for a wedding band, and has a design in mind that uses 7 ~3pt diamonds (for ~0.25 total carat weight). We''re having the ring made by a local goldsmith who we like and get along with, but I''d like to be involved with the diamond picking.

So I know all about the HCA, ideal-scope, and the rest of the tools, but I doubt these really apply to such tiny diamonds. (It''s not as if they will be cut precisely enough to have H&A, or have Sarin measurements to really do an HCA analysis either.)

1. What is the best way to evaluate ~3pt diamonds?

2. The jeweller says that she''s found that although cut is very important for regular sized diamonds, clarity and color are the important factor for smaller diamonds. What do you think about this?

3. The jeweller plans to order in about 10 diamonds and then pick the best 7 for the ring. Is 10 enough; Is this an ok strategy? (I worry that getting seven of equal size will be hard enough never mind evaluating for quality too)

Thanks,

Steve

 

[JohnQuixote]

Hi Steve.

Melee are often selected via the experienced eyes of an expert and a leverage gauge/sieve. Be sure those selected all have precisely the same spread (2.0 mm for 3 pointers). That is crucial. The girdles should be uniform and depth/table should match - don’t allow one with a flat open table and another with a heavy crown, for instance. Color does take on more importance in smaller goods because, though cut is always the priority, as you get smaller there is less reflective surface area. Regarding clarity, VS2 and higher is desirable; the goal is eye-clean. It’s nice that you may get to be involved in the process. It should be instructive and fun.

You're from Antwerp eh? Hope you got you some waffles!

 

[Garry H (Cut Nut)]

On a recent buying trip I purchased 60 diamonds with atotal weight of .20ct. That makes each stone about 1/10th the weight of your stones.
I used the Ideal-scope and rejected about 7 out of 10.

We select every diamond for cut because it makes more difference than anything else.

Stay above H color, and SI1 clarity and you will have very nice bright stones.

 

[WinkHPD]

Gary and John are correct, cut is paramount. The new desktop ASET makes a great selection tool as you can see how the diamond is going to collect and disperse the light.

I recently had two parcels come in, both touted as H&A''s. One parcel was in fact almost all H&A''s of 90% or better, which is pretty fab for smalls, but the other was only about four stones out of ten that had 90% or better H&A''s. (Two of those were "accidentally" true H&A''s which was shocking to me that such a small stone would actually be H&A)

The fun part was that you could put several of these tiny diamonds on the ASET tool and instantly see which merited being put in the reject pile and which were worth taking a better look at. Larger stones must be looked at one at a time, but with the smalls you can get many into the center of the stage for quick separation.

One thing to consider with smalls. If you get a stone that is all red and green, with little or no contrast, it is not as important to have contrast in the smalls. Little bright balls of fire are okay, as you are not looking for as much scintillation as you would be in the larger stones. Heck, with some of the tiny stones, a single sparkle IS the scintillation. (I know that is scientifically incorrect, but from a 0.005ct diamond if you get one sparkle you are doing just fine, most of them look like powdered dust.)

Wink