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Bruted girdle vs. faceted: visual affects

Discussion in 'RockyTalky' started by LightBright, Feb 16, 2019.

  1. LightBright
    Shiny_Rock

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    by LightBright » Feb 16, 2019
    Hi. I’m interested in how a frosted (bruted, opaque) girdle vs. a polished, or faceted polished girdle affects the look of a colorless diamond. I’ve heard the idea that a frosted girdle can make a darker stone look lighter and was wondering about affects on colorless diamonds.

    In a colorless diamond, does the girdle play a part in light return. Does more or different light get into the stone with each type of girdle (eg frosted, single facet polished, multi faceted polished) and is that a positive affect? Does the type of girdle affect visible girdle lines, etc.? If a frosted girdle is faceted and polished, would that change how the diamond looks aside from the girdle itself?

    Also, how much weight is lost by just polishing a bruted girdle into a single facet girdle. VS how much lost in full faceting and polishing? Should you facet or brute a diamond if you are interested in weight retention?

    Has anyone here polished or faceted a bruted girdle and regretted it, or conversely thought it improved their stone?

    Thank you for any observations you might have on this!
     
    


    


  2. Karl_K
    Ideal_Rock
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    by Karl_K » Feb 16, 2019
    My opinion is that in the ideal cut range MRB with a reasonable girdle it makes little difference for normal viewing angles.
    Steep deep diamonds or a stone with a huge girdle it could make a larger difference
     
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  3. EvaEvans
    Shiny_Rock

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    by EvaEvans » Feb 16, 2019
    As I know, there are only 3 types of diamond girdle: bruted, polished or faceted.
    Yes, girdle plays a part in the light return.
    However, I will not facet the girdle of any Old Cut diamond. I will not even buy an old cut diamond with faceted girdle, except for the newly branded Ideal old cuts.
    MRB diamonds do not have bruted girdle.
    Bruted girdle means that the diamond surface on the edge is left as it was in the original diamond crystal. Bruted girdle is a proof that this diamond is an original Old cut. I really doubt that all "old cut" diamonds on the market today are so old.
    As a collector of old cut diamonds I would advice not to touch the girdle. Many owners of old cut diamonds make the mistake to improve these diamonds. They re-polish and re-cut to remove the small chips, nicks and abrasions. However, any eye-clean imperfections in the old cuts should be left as they are, because exactly these signs of the time prove these diamonds as originally old cuts.
     
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  4. Karl_K
    Ideal_Rock
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    by Karl_K » Feb 16, 2019
    If someone wanted create old cuts its easier to leave a bruted girdle than any other kind.
    There are mrb stones cut with frosted girdles, its polished enough to remove the bearding but is not highly polished.
     
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  5. SandyinAnaheim
    Brilliant_Rock

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    by SandyinAnaheim » Feb 16, 2019
    I've purchased MRB in jewelry pieces recently that were bruted and didn't like it. It doesn't prove that it is an "original old cut", IMHO, it is a sign of an unfinished polish in modern stones.
     
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  6. elliefire99
    Brilliant_Rock

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    by elliefire99 » Feb 17, 2019
    In terms of the science of light return and faceting, I can't comment, but I did recently have a bruted girdle on an OEC faceted.

    Normally I am of the same opinion as EvaEvans regarding the girdles of old cuts. I prefer to leave them as they are, purely for history and preservation reasons (just personal preference). In this case though, the girdle was extremely thin (essentially non-existent), so I faceted it for security's sake.

    DK faceted the girdle for me, and said I could expect to see more fire with the faceting girdle. Seeing the stone after, I think I am inclined to agree. In my case, the color visibly improved, but DK said that that can go either way. In his experience, stones can go up or down about half a color grade with faceting the girdle.

    In terms of weight loss, it was very minimal. The stone was just over 2.02cts, and in the end, I lost about 0.07cts.

    I don't really see a good reason to avoid faceting for a modern cut stone.... But not an expert!
     
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  7. TreeScientist
    Brilliant_Rock

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    by TreeScientist » Feb 17, 2019
    Interesting that the color improved, and that DK said the color can go either way with faceting. I've always heard that many cutters decide to leave the girdle bruted/polished on lower colored diamonds to improve the color, as faceting usually results in minor color entrapment.
     
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  8. motownmama
    Ideal_Rock

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    by motownmama » Feb 17, 2019
    My girdle is bruted - no, really!
     
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  9. LightBright
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    by LightBright » Feb 17, 2019
    Thanks Elliefire! Do you have any before and after photos of your OEC you could post? Also, did you repolish the entire stone as well as facet the girdle? Or just facet the girdle? Just curious about what it looked like before, then after.
     
    Last edited: Feb 17, 2019
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  10. LightBright
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    by LightBright » Feb 17, 2019
    Does anyone know which type of girdle cuts off more weight? Faceting and then polishing or bruting and then frosting? If someone had a girdle they wanted to clean up while retaining the most diameter/ weight, would faceting or bruting be the first advisable step? For example is it better to brute, then facet if you don’t like it, or facet, then brute if you don’t like it. I know these are REALLY geeky questions of me but a cutter might know. A very respected PSer once told me that when they faceted their OEC, the light turn from around the girdle was a little distracting. Does the faceted or polished girdle create internal flashes of light? I’m assuming a frosted girdle occludes light coming in from the girdle.
     
    


    


  11. Dancing Fire
    Super_Ideal_Rock

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    by Dancing Fire » Feb 17, 2019
    [​IMG]
     
  12. elliefire99
    Brilliant_Rock

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    by elliefire99 » Feb 17, 2019
    Hmmm.... that makes sense. DK mentioned in passing, that sometimes with the rely old stones, after more than 100 years of wear, the bruted girdles can sometimes collect a bit of dirt that is just impossible to clean off completely. With ththe faceting it gets removed.... perhaps for that reason?

    I just had the girdle faceted, nothing else. The stone was otherwise in good condition and didn't need much else.

    I posted before and after photos in ththe thread here: https://www.pricescope.com/communit...dations-for-unmounting-a-delicate-oec.246583/
    Unfortunately, these quick snaps don't really do the after stone justice, since the light is pretty dark. I unfortunately don't have the stone anymore for better photos, but if you really want I can link some videos.
     
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  13. LightBright
    Shiny_Rock

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    by LightBright » Feb 17, 2019
    Thank you so much Elliefire! If you have a before and after video, I think it would be really educational to see the difference. But I understand if that too much work. Thank you for the before and after photos, they are much appreciated and very informative. :)
     

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