Newbie question(S)..

[DND168]

Greetings all.

Let me first start of by saying prior to lurking around this site, I have no knowledge of diamonds other than the basic 4 C''s, but I would say I am in a better position now after reading and learning a lot from the members of the forum. Very very imformative site.
Okay, I just have a few questions:

1) While in the market for a engagment ring, I found that most stones I saw were GIA certifiied, but have since learned that it is better to buy a AGS stone because I dont have to request an additonal Sarin report in order to get all the measurements of the stone? Would you agree?

2)can a stone be certified by both labs?
3) Does the date of certifcation affect price of the stone? (I saw 2 similiar stone, one was newer than the other, but considerably a big price difference)


I am trying to understand the AGS000 grading. To get the most "fire" out of a diamond, one would have to search for a Table % of 53-58 and a total depth of 58-62.3%. Can a stone containing a 58% table and 58% depth still be a 0 rated stone? In other words, any stone that falls within the given range will be a good stone right?
Lastly, a Class1A ags stone gets more into specifics with crown height, angle, pavilion and so on... do they have to fall into that range as well for a stone to be perfect( reason i ask is because when you do a stone search on Pricescope, it does ask you about these ranges, it only requires you to input table and depth %)

Sorry for the amount of questions, but I am trying to get as much info as I can in the amount of time I have...
Any input/comments would be much appreciated. Thanks for reading!

 

[Regular Guy]

Sorry for the amount of questions, but I am trying to get as much info as I can in the amount of time I have...

That''s so really what it''s about, isn''t it?

You may find that shopping at places that have equipment to give you the info missing from GIA certs is a strategy to help mitigate the absence of info from those options.

See the link below my signature for more on that.

Regards,

 

[belle]

hey dnd, welcome to ps!

Date: 9/22/2005 8:11:20 AM
Author:DND168

1) While in the market for a engagment ring, I found that most stones I saw were GIA certifiied, but have since learned that it is better to buy a AGS stone because I dont have to request an additonal Sarin report in order to get all the measurements of the stone? Would you agree?

at this point, ags and gia grade differently.
for the average shopper, the gia grading report that contains information on the 4c''s is sufficient.
for someone that wants more information on cut, including crown and pavilion angles, an ags grading report can supply that information. the newer ags reports also grade light performance.

Date: 9/22/2005 8:11:20 AM
Author:DND168

2)can a stone be certified by both labs?

yes it can, but it may not receive exactly the same grade.

Date: 9/22/2005 8:11:20 AM
Author:DND168

3) Does the date of certifcation affect price of the stone? (I saw 2 similiar stone, one was newer than the other, but considerably a big price difference)

to some extent, yes, but there are many other factors that would go into the pricing equation.

Date: 9/22/2005 8:11:20 AM
Author:DND168

I am trying to understand the AGS000 grading. To get the most ''fire'' out of a diamond, one would have to search for a Table % of 53-58 and a total depth of 58-62.3%. Can a stone containing a 58% table and 58% depth still be a 0 rated stone? In other words, any stone that falls within the given range will be a good stone right?
Lastly, a Class1A ags stone gets more into specifics with crown height, angle, pavilion and so on... do they have to fall into that range as well for a stone to be perfect( reason i ask is because when you do a stone search on Pricescope, it does ask you about these ranges, it only requires you to input table and depth %)

Sorry for the amount of questions, but I am trying to get as much info as I can in the amount of time I have...
Any input/comments would be much appreciated. Thanks for reading!

to my knowledge, a stone with a 58% table and a 58% depth could not get an ags000 rating. it''s just not a combination that would work for optimum performance.

when you do a search on ps, use the ''cut quality search'' button. this feature will bring up results that include the hca score for each. scores under 2.0 on the hca are considered ''ideal''.

 

[DND168]

belle, thanks for your answers... this makes a lot of sense now..
One last question... do measurements matter? how do they come into play in terms of fire and bling?

I.E. Measurements: 6.48 x 6.21 x 4.22

 

[belle]

measurements matter a great deal. for example, the measurements you posted above would be indicative of a stone that is out of round. i don''t know if it is even possible to come up with a good performing stone that is out of round like that. unless those measurements are for another shape.

 

[DND168]

Belle, where can i find more information on round measurements? I cant seem to find them on this site.. nor forum topics..

can you provide me with some good ranges for measurements on round stone.

 

[strmrdr]

This should help:

https://www.pricescope.com/community/threads/whats-the-difference-between-super-ideal-ideal.26216/

 

[DND168]

Can you please help me breakdown what each number stands for"

6.48 x 6.21 x 4.22

above is just an example..

 

[strmrdr]

6.48 largest diameter
6.21 smallest diameter
4.22 depth.

Depth percentage would be ((depth/smallest diameter)x 100)
((4.33/6.21) x 100)

using largest diameter - smallest diameter
Generaly anything over .10 I consider out of round and for super-ideals I look for .5-.6 range.
.27 would be eye visible.
Its not that common to see it that high I wonder if its a typo in the specs.

 

[DND168]

Sorry, 1 last question on this topic.

the last figure is depth.. which depth are you referring to and how does this figure factor into the cut of the stone.

Thank you so much, and sorry for the multiple questions.

 

[strmrdr]

the drawing on this AGA cert clearly shows whats being measured where:

 

[strmrdr]

Date: 9/23/2005 10:54:28 AM
Author: DND168
Sorry, 1 last question on this topic.


the last figure is depth.. which depth are you referring to and how does this figure factor into the cut of the stone.


Thank you so much, and sorry for the multiple questions.

The most important angle measurements are the crown and pavilian angles they along with the table % and the girdle percentage determin the depth of a diamond.
There are depth % ranges that the known good combo of angles fall into when they have thin to med girdles so its a way to begin to sort them out.
Find the ones with the right depth then look at the angles from there.
Thats all it does is get you into a range where a good combo might be it doesnt tell you what the angles are.

 

[DND168]

Excuse me for being so dumb, but are you saying the last digit on the dimension/measurement of a diamond is derived from the crown and pavillion angles along with table% and gridle of the stone?
Should I be overly concerned with these numbers. I know if the large-small is <.06 i should be find no?

 

[Regular Guy]

Date: 9/22/2005 3:57:52 PM
Author: DND168
belle, thanks for your answers... this makes a lot of sense now..
One last question... do measurements matter? how do they come into play in terms of fire and bling?

I.E. Measurements: 6.48 x 6.21 x 4.22

Danny, this robust HCA utility may really help you the most in understanding how the specified measurements work together.

Regards,

 

[strmrdr]

Date: 9/23/2005 11:57:27 AM
Author: DND168
Excuse me for being so dumb, but are you saying the last digit on the dimension/measurement of a diamond is derived from the crown and pavillion angles along with table% and gridle of the stone?

Should I be overly concerned with these numbers. I know if the large-small is <.06 i should be find no?

in your example the depth 4.22 is actualy measured.

But the factors that determin what the number is are the crown and pavilian angles, table % ,the girdle, and to add another thing in the culet (point at the bottom) of the diamond.

The diamonds with the best angles will usualy be found in diamonds that have a depth between: 59 – 61.8% with the very best often in the 60.6% to 61.8% range.

 

[aljdewey]

Date: 9/23/2005 11:57:27 AM
Author: DND168
Excuse me for being so dumb, but are you saying the last digit on the dimension/measurement of a diamond is derived from the crown and pavillion angles along with table% and gridle of the stone?
Should I be overly concerned with these numbers. I know if the large-small is <.06 i should be find no?

Let's try it this way.

Let's look at this 1.25 ct. diamond.

It's measurements are 6.97mm - 7.01mm x 4.23mm
It has 60.5 depth, 55% table, 34.6 crown angle, and 40.7 pavilion angle.

Most diamonds aren't a perfect circle, so when they measure diameter (edge to edge), they measure the shortest diameter and the longest diameter. These are the first two numbers. At it's widest point, the diameter on the above diamond is 7.01mm. On it's shortest diameter, it measures 6.97mm.

The last number - the 4.23mm....is the measurement of the diamond measured from the table down to the culet (the perpendicular measurement) expressed in millimeters.

The depth percentage - 60.5% - expressed as a percentage how deep the stone is relative to its girth. 4.23mm (its depth measurement) divided by its *average* girth measurement of 6.99 (6.97+7.01mm divided by 2 = 6.99mm) equals 60.5%....the total depth of the stone expressed as a percentage.

The table - 55% - means that the table width accounts for 55% of the total width of the stone.

The crown/pavilion angles measure the angle measurements of the stone relative to the horizontal plane of the girdle.

Depth is important because stones that are too shallow don't reflect light well and tend to lack fire. Stones that are too deep tend can leak light, making the diamond appear less sparkly.

Generally, most folks prefer stones in the 60% to 61.9% or so depth.....helps give the best "spread" of the stone. Some like to stay below 61%.

Hope all this helps you understand what you are seeing on these reports.

 

[DND168]

Thanks for the detialed explanation.. this definitely clears up a lot.
Stay tuned as I will be back for advice on stones im looking at. Thanks.