ASET advice

[lepetitematin]

How do people feel about the ASET for this diamond? Is there too much blue?

http://www.goodoldgold.com/diamond/8913/

 

[slg47]

How do people feel about the ASET for this diamond? Is there too much blue?

http://www.goodoldgold.com/diamond/8913/

ASET looks great. if you are interested in this diamond, ask if it is eye-clean.

 

[lepetitematin]

What does the blue mean exactly? That there will be shadows there sometimes? all the time? Bowties? I've read descriptions of ASET so I know it stands for contrast, but I don't know what that means practically speaking -- in other words, how the "blue" areas will look to the eye...

 

[diamondseeker2006]

No, no shadows. If you look at the diamond xray image, you can see that all of the stone is red showing no leakage. When you move a stone around, different facets reflect light. That is an outstanding stone. I don't think there is a bad performing AVC. It's really a matter of choosing the size, color, clarity, and shape you want!

 

[lepetitematin]

So when I move the stone around, what would the areas depicted in blue look like versus the areas depicted in red or green?

 

[John P]

So when I move the stone around, what would the areas depicted in blue look like versus the areas depicted in red or green?

Blue is obstructed light (in the static position, light blocked by the viewer's head). When the stone is tilted obstructed areas will come to life (become red) and other areas (currently red) will become obstructed. As you continue to tilt the diamond they will swap again, and again, and so on. In normal viewing this rapid "on-off" effect is what we perceive as scintillation.

It's a great ASET. Looks like a killer stone.

 

[lepetitematin]

Thanks John! What do you think about this one? Obviously not as big as the 1.94, but better clarity http://www.goodoldgold.com/diamond/9088/#script

 

[John P]

Thanks John! What do you think about this one? Obviously not as big as the 1.94, but better clarity http://www.goodoldgold.com/diamond/9088/#script

Performance will be very similar; with a slight (technical) edge to the 1.94 in terms of brightness - this on both the GOG ASET and the AGSL 3D-generated ASET. It may be so slight as to be negligible in most viewing conditions, but the technical difference exists.

Clarity: Ask GOG to discuss the SI2 xtl, plotted clouds and clouds not-shown. AGS is pretty strict on clarity and 'not shown' usually indicates that the characteristic is a non-factor, but it's always good to have a seasoned gemologist on-your-side to look at the stone in question.

It's interesting that the grade-setting inclusion for both is a xtl, with cloud and feather as secondary and tertiary...yet they are two clarity grades apart on the whole.

Setting aside all the minutia above, I think either stone will be a winner.

 

[lepetitematin]

I didn't realize that the order of the types of inclusions in the Key actually matters -- interesting. How do they decide which is primary, secondary, tertiary -- the size/obviousness of the inclusion?

Also, what about the ASETs tells you that the 1.94 is going to be technically brighter than the 1.67?

Thanks again for this - very helpful!

 

[John P]

I didn't realize that the order of the types of inclusions in the Key actually matters -- interesting. How do they decide which is primary, secondary, tertiary -- the size/obviousness of the inclusion?

Also, what about the ASETs tells you that the 1.94 is going to be technically brighter than the 1.67?

Clarity grading factors include size, quantity, position, type and visibility of the blemishes/inclusions; a diamond with a single large feather or dark/visible crystal could receive a lower clarity grade than one with numerous pinpoints or tiny transparent crystals. In this case I'd presume size/position/visibility are the difference-makers, but every diamond is different so best to ask an expert who has it in-hand.

RE brightness: Don't read too much into my comment. The AGSL ASET shows more red (overall), which is factored into the lab's brightness score when setting the performance grade. But these diamonds will never be viewed in a single still position; they will be seen in-motion through many different illumination scenarios. There is enough balanced brightness and obstruction (red & blue) in both stones to earn the AGS0 grade - which was determined using a range of tilt, by the way - I'm sure both are top performers.

Thanks again for this - very helpful!

You're welcome.