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Please advise on this IGI-Antwerp graded LG diamond

Discussion in 'Laboratory-Grown Diamonds /Man-Made Diamonds (MMD)' started by Elsa2006, May 27, 2019.

  1. Elsa2006
    Rough_Rock

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    by Elsa2006 » May 27, 2019
    Hello everyone, I am new to this forum and certainly a novice regarding diamond properties. My husband and I are in the process of updating my mined engagement diamond to a round ideal cut lab grown diamond. There are a few things I am nervous/anxious about in this process.
    I am working with a local jeweler who frequently brings in loose diamonds to look at. Within my budget, cut/optical performance is most important to me. Unfortunately, all of the loose diamonds so far have been IGI graded so no scope images for evaluating optical performance. I just purchased a ASET scope from Pricescope and I hope I can use it efficiently.

    This week I will see the following diamond (IGI Report 341802157; please see below) that I am cautiously interested in. It has a HCA score of 1.5. Here are the specific points I am uncertain about prior to seeing it in person.

    (1) Online resources suggest that IGI-Antwerp grading is typically inflated. If this diamond is beautiful in terms of light return, do you recommend sending it to GIA for an independent grading before final purchase decision?

    (2) The pavilion angle is at the upper limit for ideal proportion (40.9°)--not sure how this will translate to optical performance when combined with the crown angle (34.5°). I like broad flashes of white light (brilliance) more than colored sparkle (dispersion).

    (3) The polish is "very good" (not excellent). How likely is this expected to interfere with light return? Or how is this expected to impact the visual beauty of the diamond (unaided eye)?

    (4) There are 3 cloud inclusions near the girdle. Are cloud inclusions generally bad for light return?

    Your expertise is highly appreciated and thank you in advance!



    REPORT NUMBER: LG_341802157
    REPORT CITY, DATE: ANTWERP, November 25, 2018
    DESCRIPTION: LABORATORY GROWN DIAMOND

    upload_2019-5-27_9-56-17.png

    SHAPE AND CUT: ROUND BRILLIANT
    CARAT WEIGHT: 3.03 Carats
    COLOR GRADE: F
    CLARITY GRADE: VS 2
    CUT GRADE: IDEAL
    POLISH: VERY GOOD
    SYMMETRY: EXCELLENT
    Measurements: 9.28 - 9.33 x 5.72 mm
    Table Size: 56.5%
    Total Depth: 61.5%
    Crown Height/Angle: 15% - 34.5°
    Pavilion Depth/Angle: 43% - 40.9°
    Girdle Thickness: MEDIUM TO SLIGHTLY THICK (FACETED)
    Culet: POINTED
    FLUORESCENCE: NONE


    Holloway Cut Advisor™

    Light Return: Excellent
    Fire:
    Excellent
    Scintillation:
    Very Good
    Spread:
    Very Good
    HCA Score :
    1.5 - Excellent - within TIC range

    Looks Like size
    upload_2019-5-27_9-56-42.png
    For more info
    Should sparkle beautifully and look a good size for its carat weight. Confirm with an Ideal-scope, ASET scope or send to an appraiser.
     
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  2. OoohShiny
    Ideal_Rock

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    by OoohShiny » May 27, 2019
    Not many MMDs are graded by GIA, unfortunately - they do grade them but only as far as 'colourless' or 'near colourless', which is not very helpful (and somewhat annoying, given they must know the colour grade in order to put it into the wider grading bands...).

    I personally speaking would therefore probably aim to go for colourless (D-F) on other grading reports, on the basis that it should at least be a GIA G or an H at the very lowest.

    Clouds in a VS2 should be fine, and being near the girdle (rather than under the table) will help the diamond look 'eye-clean'. You will be best placed to check for any impacts of the clouds as you will have it in front of you - make sure to look at it in flat lighting, away from the magic spotlights that make everything look sparkly, as that will help you assess light performance in real life.

    Polish being 'very good' should not present much issue, if any, as I understand it.

    WRT the angles, it would be useful if you can get an ASETscope image of the stone - that will help identify consistency of facet angles across the stone and any leakage areas. The crown is in the middle of the PS-recommended range and the table is on the smaller side, so both together are more likely to create coloured fire. If you specifically want white light return, you should look for lower crown angles (perhaps <33.5 degrees) and larger tables (~58%) but you may need to increase the pavilion depth when you lower the crown angle. (The HCA tool will help identify angles that work together.) A 60/60 stone (~60% table and ~60% depth) may be what you find most appealing - they are generally known for more white light than coloured fire.

    See what you think of this stone, though - if you have a balanced amount of white light and coloured fire, you could get the best of both worlds :)
     
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  3. Elsa2006
    Rough_Rock

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    by Elsa2006 » May 27, 2019
    Thank you @OoohShiny for your input and suggestions!
    I was unaware that WRT color, GIA grades as "colorless" or near "colorless". This diamond was graded as an "F" by IGI-Antwerp, which I am afraid may be inflated.

    I will try to learn how to obtain an ASET image with my phone. I downloaded the "Screen-Light" app and also purchased an examination plate from David Atlas Shop. I am excited to see what this diamond looks like in person!

    Also, thank you for the information on crown/pavilion angle combinations that may return more white light.
     
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  4. Elsa2006
    Rough_Rock

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    by Elsa2006 » May 31, 2019
    I was able to view the diamond with an ASET scope but could not take a photo. But attaching 2 indoor (jewelry store) and 2 outdoor photos on a sunny day (the diamond in question is the round ideal cut).

    1. All the proportions are within the ideal range. However, I am having concerned about the symmetry. I couldn't not distinctly see 8 defined blue arrows with the scope. Some of the arrows appeared "greyish" and was hard to focus (did not have this issue with another diamond that I compared against). In addition, I couldn't not see the contrast arrow patterning with the naked eye when I tried to view it under lots of different lighting conditions. Could symmetry issues/misaligned facets explain the phenomenon of not seeing the arrows distinctly?

    2. There appear to be more green around the girdle than I expected to see. Possibly painting/digging? Visually, I think the girdle looks contrasted/dark. There were also blue contrast areas on either side of the arrowheads under the ASET scope.

    3. Although florescence is reported as "none", curiously, the diamond had a light lilac blue hue to it under direct intense sunlight. Possibly some slight florescence? Didn't obtain a photo of this phenomenon.

    I have to make a decision soon and I am anxious that either I am passing up on a good diamond because I don't know what I am looking for or my symmetry concerns are valid.
    Thank you in advance for any feedback.

    IMG-3568.JPG IMG-3570.JPG IMG-3577.jpg IMG-3578.JPG

    CUT GRADE: IDEAL
    POLISH: VERY GOOD
    SYMMETRY: EXCELLENT
    Measurements: 9.28 - 9.33 x 5.72 mm
    Table Size: 56.5%
    Total Depth: 61.5%
    Crown Height/Angle: 15% - 34.5°
    Pavilion Depth/Angle: 43% - 40.9°
    Girdle Thickness: MEDIUM TO SLIGHTLY THICK (FACETED)
    Culet: POINTED
    FLUORESCENCE: NONE
     
    


    


  5. OoohShiny
    Ideal_Rock

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    by OoohShiny » Jun 24, 2019
    Hi Elsa,

    My apologies I didn't come back to you on this - I think my computer crashed out and I have a lot on my mind for various reasons, so I forgot you were waiting for a reply.

    Did you go ahead with the stone in the end? It looks substantial in the pictures! :)
     
  6. Elsa2006
    Rough_Rock

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    by Elsa2006 » Jun 27, 2019
    My apologies for the late response. I just checked with the jeweler, it's still avialable. The color is most definitely F (for comparison: my mined diamond in the photo, the princess cut, is an I).

    All the proportions are within ideal range and the HCA score is 1.5.

    I have two reservations, possibly due to my complete lack of expertise.
    1. If you look at the photo below, you can see my skin color in the middle of the stone. The ASET also showed me a bit of light leakage under the table. Not sure if most commercial diamonds have a little bit of leakage and how this compares. I highly appreciate any input



    2. Wondering if the symmetry is a little off because it's hard to align the 8 arrows when I am looking at it under the ASET scope. Wondering if there is too much contrast at the girdle (around where the arrowheads would be)...painting/digging? Under the ASET scope, the girdle area has quite a bit of green.




    It is a gorgeous stone in person (sparkles beautifully, just cannot see the arrows clearly defined with the unaided eye), and the trade-in value for my mined diamond is totally acceptable. I am wondering if I am overthinking things.

    Thank you for any input.

     
  7. OoohShiny
    Ideal_Rock

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    by OoohShiny » Jun 28, 2019
    HCA score under 2 indicates the angles should work together, although it doesn't necessarily mean that all the angles are the same - there could be variance in the lower facet angles that causes leakage in some facets. An ASETscope image would help determine cut accuracy and highlight any areas of leakage - do you think you'd be able to get a picture of the ASET? (Tricky to do, I know!)

    Alternatively, it could be reflecting the colour of your top or your hair or any other thing that is darker in colour, making it look dark in the centre - can you remember what you were wearing when you took the picture? :)
     
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  8. Elsa2006
    Rough_Rock

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    by Elsa2006 » Jun 28, 2019
    Unfortunately, I could not get an ASET scope image (and I'm not in the same location at the moment). All the MMDs I have seen in person are IGI graded--sadly no photographic information on optical performance.

    1. It took a lot of fiddling/tilting the scope and the diamond to pop/align all 8 arrows into view. If you look at the photos I have posted, none of them clearly show an arrow. With the unaided eye, I was never able to see the 8 arrows. This is why I am suspicious of its "excellent symmetry" grading. Your speculation about angle variations is a strong possibility.

    2. The arrows under the ASET scope appeared grayish instead of blue (similar to in the photo below). I have seen some ASET scope images where the arrows are gray. Curious as to why this difference?
    ASET.jpg
    3. I do not recall the color of the clothing I was wearing. But under the ASET scope, there was a light pink "ring of death" (not as intense as the photo above). But there were green areas around the girdle (on either side of the arrowheads).

    I know it's really difficult to provide input without adequate optical information. From your experience, how did the diamond appear in the photos? Is it more contrasted/busy patterned than ideal?
    Thank you.


     
  9. OoohShiny
    Ideal_Rock

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    by OoohShiny » Jun 30, 2019
    Hi Elsa,

    Apologies - busy weekend here!

    Without the ASETscope image for the actual stone (or a scan of the diamond, as per the discussions in another thread today) it is hard to accurately assess it - and videos/pictures are notoriously difficult to review because the conditions are always so infinitely variable!

    If the jeweller has an ASETscope, would they be able to provide you a picture?
     
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