Find your diamond
Find your jewelry
shape
carat
color
clarity
  • Pricescope Upgrade/Maintenance Is Complete.

    We still have a few things to iron out. If you see any bugs, issues or have any concerns, let us know here in this discussion.

independent gemologist appraisal what to ask for???

Status
Not open for further replies. Please create a new topic or request for this thread to be opened.

scarleta

Brilliant_Rock
Joined
Feb 25, 2006
Messages
1,572
Hello: I am wondering what I should ask for when taking a loose stone for 2nd opinion/ certificate confirmation. The stone has GIA appraisal , but I am not sure what to ask for ? Many thanks.
 

Sponsored By:

Related topics:

Regular Guy

Ideal_Rock
Joined
Jul 6, 2004
Messages
5,951
Between the first & second pages, there''s 3 substantive threads in the FAQ section here you may well want to look into.
 

kenny

Super_Ideal_Rock
Premium
Joined
Apr 30, 2005
Messages
26,953
GIA has two locations.
One is in NY NY
The other is in Carlsbad California, near San Diego.

If you live nearby call them.
Make an appointment to take your GIA report and diamond to them yourself.

I did this and got a laminated letter of confirmation from GIA.
I dropped off the diamond in the morning and picked it up that afternoon.
It cost $75. (Or maybe it was $45, I'm getting old.)


Today I am more comfortable verifying a stone myself.
I have access to a measusing microscope, with dial micrometers on the stage, that is very accurate.
I also have access to a gemological scale to verify the weight.

If the weight and dimensions match the report, then it has to be a real diamond.
A CZ or glass cannot weigh the same and have the same dimensions.
A diamond has a unique density, which is weight for size.

Next if inclusions match the report you have a match.
There, that saves me some money.

You may get a local jeweler to weigh and measure the stone free if you consider having them set it.

Also jewelers and pawn shops have diamond testers.
 

scarleta

Brilliant_Rock
Joined
Feb 25, 2006
Messages
1,572
One more question with regards to second appraisal / comparison to GIA report.
Would one show the stone and the gia appraisal together or only the stone?
 

diamondseeker2006

Super_Ideal_Rock
Premium
Joined
Jan 11, 2006
Messages
55,052
Date: 1/5/2007 2:22:34 PM
Author: scarleta
One more question with regards to second appraisal / comparison to GIA report.
Would one show the stone and the gia appraisal together or only the stone?
The first stone I ordered had an old cert so I took it to a local jeweler with the cert to have them confirm that the stone matched the cert. They did it for free while I stood there.
 

Richard Sherwood

Ideal_Rock
Joined
Sep 25, 2002
Messages
4,924
I sometimes take flak for this, but my opinion is that when someone brings me a diamond for my "independent opinion", that''s exactly what I should give them. An independent opinion, which they can use in conjunction with any other documentation (major lab report, etc.) to base their purchase decision on or just have a better understanding of the gem they own.

Therefore I usually ask clients to let me do my analysis first, and then we compare my findings with any existing documentation they have. Any minor differences are usually understandable and easily explained, any major differences we go back and take a second look at, trying to get a feel for the reason why.

I tell clients "let''s say for example I grade the diamond as an "F" color, and GIA grades it as a "G" color. Then you know at the least that you have a very high "G" color diamond."

You see what I mean? It gives the client a better feel for the diamond. Most seem to appreciate this approach.
 

RockDoc

Ideal_Rock
Joined
Aug 15, 2000
Messages
2,509
I agree with Richard, but most of the time sellers send the reports to me.

If the customer is an in person one, it is their choice, whether I see the grading report first or not.

If it''s a long distance client, I can look at the report first, but even if I do, it isn''t going to change my mind from agreeing or disagreeing.

I also take 3-4 scans of it in the colorimeter, besides checking the stone against master diamonds too, in several positions.

I have had stones come in that are way off from their reports. Some stones come in that haven''t been graded by a major lab, and occasionally one that my eyes and the grading reports as compared to my eyes and the colorimeter I feel are better.

I suppose all appraisers with colorimeters or SAS machines do the same thing.

With Richard and David having the printouts from the SAS that substanciates gradings by an appraiser as well.

Rockdoc
 

scarleta

Brilliant_Rock
Joined
Feb 25, 2006
Messages
1,572
Thanks so much if you were closer I would definitely take the stone to you..I guess I have to make sure they have colorimeter or SAS machine ( whatever that is?) Many thanks..
 

Richard Sherwood

Ideal_Rock
Joined
Sep 25, 2002
Messages
4,924
Date: 1/5/2007 9:59:31 PM
Author: scarleta
Thanks so much if you were closer I would definitely take the stone to you..I guess I have to make sure they have colorimeter or SAS machine ( whatever that is?) Many thanks..
This information is from Marty Haske's site, the developer of the SAS2000 spectrophotometer:

"The SAS2000 provides the most accurate colorimetry instrumentation available today for diamond color grading and produces a consumer oriented analysis which shows the WHY of a diamond color grade.

The SAS2000 combines a state of the art, dual channel fiber optic spectrophotometer with an approximate optical resolution of 1.5nm. The 400nm to 950nm band is quantified in approximately 0.3nm intervals, approximately 8 times finer than the next closest single purpose colorimeter. A DUAL channel system accurately tracks with the reference channel any variations in the illumination source spectra, in contrast to single channel colorimeters.

The SAS2000 is a high resolution system which utilizes GIA/GTL graded diamond master stones for its color grading calibration and a numerical grading system (0-10) consistent with the AGS colorimeter scale reading. Grading a diamond is a simple procedure which results in an estimated grade based on multiple mathematical comparisons from established color science theory as well as modeling of the visual grading process.

The SAS2000 additionally incorporates a special UV blocking filter so that color grading can be done without blue fluorescence influencing the grade."

You could contact Marty to see if there's an appraiser in your area with the SAS. His website is: [email protected].
 

Modified Brilliant

Brilliant_Rock
Trade
Joined
Mar 24, 2005
Messages
1,479

I also prefer to perform my own analysis first, without looking at the diamond grading report.


Any differences can be explained but usually a consumer wants an independent confirmation of


their purchase or pending purchase.


www.metrojewelryappraisers.com

 

scarleta

Brilliant_Rock
Joined
Feb 25, 2006
Messages
1,572
Thanks Richard do you know if I can find anyone who uses it in Canada? , or only USA ? Thanks again
 
Status
Not open for further replies. Please create a new topic or request for this thread to be opened.
Be a part of the community It's free, join today!

Need Something Special?

Get a quote from multiple trusted and vetted jewelers.

Holloway Cut Advisor



Diamond Eye Candy

Click to view full-size image.
Top