Marquise Diamond Questions

[Roger1011]

Hi All

I am in the process of purchasing a Marquise Diamond. I have seen a stone I like. Vital Stats:

1.55 carat

Depth %: 57.5%

Table %: 54%

Symmetry: Good

Polish: Good

Girdle: Medium to very thick

Culet: None

Fluorescence: None

Measurements: 12.02 x 6.37 x 3.66 mm

Length/width ratio: 1.89


Is this a good stone for an engagement ring. I would welcome any assitance as I have bee around many jewellers in the Uk and have so many different opinions.

Best Regards

 

[oldminer]

It is a bit shallow for maximizing light return although it is a very good size for its carat weight due to not being overly deep. You should shop more before deciding on this one although you may end up liking it best.

 

[Rockdiamond]

HI Roger,
I do not believe it''s productive trying to judge a diamond based on measurements.
Although I would not recommend the diamond based on the measurements, neither would I knock it.
I''ve seen many amazing marquise stones with depths similar to the one you''ve seen.
If you''ve seen it and love it ( and the seller is reputable, and price competitive) it sounds fine to me!


Does the stone have a GIA report?

 

[Todd Gray]

Date: 6/15/2009 6:37:57 PM
Author: Rockdiamond
HI Roger,
I do not believe it''s productive trying to judge a diamond based on measurements.
Although I would not recommend the diamond based on the measurements, neither would I knock it.
I''ve seen many amazing marquise stones with depths similar to the one you''ve seen.
If you''ve seen it and love it ( and the seller is reputable, and price competitive) it sounds fine to me!

Does the stone have a GIA report?

Roger has the advantage of having seen the diamond in-person so the measurements of the diamond are not as critical as they would be if he were shopping for the diamond online. However there is a definite correlation between the measurements for each section of a diamond and in this case, that is all that Roger has really given us to go on... We''ve been asked "is this a good stone for an engagement ring" but there are some significant pieces of the puzzle that are missing and they are actually critical in terms of being able to provide any real advice:

What are the measurements for the crown and pavilion angles? These are the two opposing surfaces that dictate so much of how a diamond will perform visually and to what degree it will be brilliant or dispersive.

And I don''t see a clarity, color or fluorescence grade... What is the clarity? What are the inclusions? Where are they located and to what extent do they impact the diamond? Do you have a copy of the lab report that you can post?

That said, I think the fact that Roger has seen the diamond and likes it is a pretty good place to start! I think that comparing this diamond to one with a little more depth as Dave suggested is appropriate. As I recall, the preferred range for total depth that Dave indicated on his early cut grading charts for marquise brilliant cut diamonds was in the range of 59 - 63% so this one is close, but like I said some pieces of the puzzle are missing.

 

[Lorelei]

Hi Roger

If you want to look around some more, contact Dr Indira Marchant at

www.bestdiamonds.co.uk

She is in London if that is convenient for you.