ASET question

[sampras]

I was looking at stones today at a local store and the owner of the store showed me his new ASET. We looked at an ideal cut stone and there was some blue near the center of the stone (and not any in the arrows). He told me that blue was bad and indicated that this was extinction, and didn''t really go into any more detail as to what to look for. After searching for ASET in the forums here, it looks like blue is not bad, and the arrows should be blue. Is this true? We were looking at a 90 point stone. We then looked at a 71 point stone, which if I remember correctly had more blue in the arrows. I remarked that there was more blue in this one, which at the time I thought was bad, and he immediately put it away (it was of course $1500 cheaper). I am frustrated beyond belief with going to these B&M stores and the people not having a clue as to what they are talking about. This was the owner of the store, and a friend had recommended I talk to him, and he does not even seem to know what he''s talking about and it seemed like he just wanted me to buy the stone that was more expensive.

Does anybody have any insight as to whether he was interpreting the ASET image incorrectly??

Thanks.

 

[JohnQuixote]

Date: 11/17/2005 12:08:24 AM
Author:sampras
I was looking at stones today at a local store and the owner of the store showed me his new ASET. We looked at an ideal cut stone and there was some blue near the center of the stone (and not any in the arrows). He told me that blue was bad and indicated that this was extinction, and didn''t really go into any more detail as to what to look for. After searching for ASET in the forums here, it looks like blue is not bad, and the arrows should be blue. Is this true? We were looking at a 90 point stone. We then looked at a 71 point stone, which if I remember correctly had more blue in the arrows. I remarked that there was more blue in this one, which at the time I thought was bad, and he immediately put it away (it was of course $1500 cheaper). I am frustrated beyond belief with going to these B&M stores and the people not having a clue as to what they are talking about. This was the owner of the store, and a friend had recommended I talk to him, and he does not even seem to know what he''s talking about and it seemed like he just wanted me to buy the stone that was more expensive.

Does anybody have any insight as to whether he was interpreting the ASET image incorrectly??

Thanks.

Hi Sampras.

Here is a thread with info on the ASET. The 4th and 5th posts down describe how to interpret the colors you see.

I will assume you''re talking about round diamonds. If you have viewed ideal-scope images you can think of the blue areas in the ASET as similar to what you would see as black in the ideal-scope. In both instances those dark areas represent light that would normally be drawn from, and returned, at extremely high angles. They are dark in these scopes because your head - or the camera - is blocking that light from entering when you view the diamond.

In diamonds with good optical symmetry the dark areas represent arows. This light is drawn directly from the pavilion mains, the engines that drive light return, and is very important.

 

[WinkHPD]

The blue indicates the area of head shadow. It is important that the stone be cut so that there be a balnced amount of these areas so that you have good contrast in the stone. It is the contrast that gives you the sparkle as facets blink on and off as the stone is moved. If all the facets were on all the time you might as well have a small mirror in your ring. All bright all the time, and very boring. You want the patten to be not all in one place though, as then you would have a lump of darkness in your stone, rather than a myriad of on/off flashes. One of the reasons that the H&A cut stones look so good is that the pattern is very evenly distibuted, creating great sparkle with even the tiniest of movements. It is entirely possible to have great looking stones without the H&A pattern also, and these stones will show a great mix of blue and red in the center of the stone.

Your jeweler is to be commended on at least having an ASET, that puts him in a very small minority at this time, but now he needs to spend the time to learn to properly use it, then he can be in the vangard rather than just another jeweler with a new toy.

Wink

 

[valeria101]

Date: 11/17/2005 12:08:24 AM
Author:sampras

We looked at an ideal cut stone and there was some blue near the center of the stone (and not any in the arrows).

Well, what do they call ''ideal''? Your description makes me think of something rather different - a cut fault called ''nail head''.

The ASSET image may have been distorted by some freak viewing conditions too. Were you using the hand held ASSET (small plastic tube) or desktop (light box on which you have to place the diamond table down on a screen) ? I suspect that the hand held version takes a bit of practice to use and if not held correctly, there''s no telling what you''ve seen. Actually, perhaps it is possible to identify what happened, but I have not tried it yet.

Hearing ''ideal cut'' - I would imagine there are typical H&A involved. Even if the pattern is not textbook perfect. It is not that I believe all beautiful round diamonds are H&A, but this is what there is a premium for, so the language matters.

Hope some of this makes sense.

 

[valeria101]

Does any of these look familiar?

 

[sampras]

Thanks a lot everyone for your replies. I will probably go back and take another look at it now that I know what I am looking for and may even educate the owner of the store on what to look for