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Does Hearts and Arrows follow certain dimensions?

Discussion in 'RockyTalky' started by bananaboy, Dec 4, 2008.

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  1. bananaboy
    Rough_Rock

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    by bananaboy » Dec 4, 2008
    I have the following dimensions:

    table 58
    depth 60.4
    pav 41
    crown 33.5

    HCA 1.1

    I asked the local jeweler if it was hearts and arrows and she said it was. I asked for a pic but she said the broker in NY did not have the equipment to take a pic but did have the scope to view it.

    Does Hearts and Arrows follow some strict dimensions it must fall within?

    I read in another thread that some ppl want these specs:

    "I look for specifically are rounds with crown angles between 34 - 34.7 with pavilion angles around 40.7-40.9 with tables between 53-57% "

    I checked randomly some hearts and arrows at some online retailers and most fall within the above specs.
     
    


    


  2. neatfreak
    Super_Ideal_Rock

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    by neatfreak » Dec 4, 2008
    Unfortunately as far as I know there are no dimensions that will tell you if a stone is H&A or not. But I wouldn't buy it without a picture if you want H&A. There are dimensions that indicate a well CUT stone, as you've noted, and a super ideal cut stone is likely to exhibit some form of H&A, but it isn't guaranteed.
     
  3. Wink
    Ideal_Rock
    Trade

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    by Wink » Dec 4, 2008
    Hearts and Arrows are a pattern seen in a special viewer, not dimensions. It is possible to have a perfect H&A pattern and not have an ideal cut diamond and it is possible to have an ideal cut diamond and not have a H&A pattern.

    Even many jewelers do not seem to understand this.

    Wink
     
  4. Garry H (Cut Nut)
    Super_Ideal_Rock
    Trade

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    by Garry H (Cut Nut) » Dec 4, 2008

    The revised h&A''s tutorial might help a bit.


    Also someone with time might find the pdf''s on HRD''s site with alll their material.



    Even better still, someone here might write and submit for review a journal article simplifying and explaining HRD''s new H&A''s grade system. all the proportions are there - from memory they go from below 30 crown to over 36 degrees

     
    


    


  5. Paul-Antwerp
    Ideal_Rock
    Trade

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    by Paul-Antwerp » Dec 5, 2008
    Please do not have anyone posting the HRD-pdf''s.

    I have seen respectable professionals regard them as proportions guaranteeing H&A, while they just show proportion-combinations where H&A is theoretically possible.

    I think that we already have sufficient criteria, where people think the following: ''Because this limited set of information CAN produce a great stone, the stone with this set of information WILL be a great stone.''
     
  6. strmrdr
    Super_Ideal_Rock

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    by strmrdr » Dec 5, 2008
    The only way to know a diamond is h&a is to see the heart view in a h&a viewer or an image taken under such with one exception that very few people in the US have access to PERIOD!
    The only exception is a helium scanner based gem/dmc file can come close enough in most cases but again it comes down to viewing an image of the diamond just in this case a virtual one.
    Sarin based gem files will not do for this.
     
  7. Garry H (Cut Nut)
    Super_Ideal_Rock
    Trade

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    by Garry H (Cut Nut) » Dec 5, 2008
    Paul all I was asking for was somone to link to HRD''s information where they have several pdf''s (4 tutorials?) But the information is in need of explanation.
    HRD will give permission for educational usage if somone does wish to write it up for the Journal section here I am sure we could have their agreement (They gave me permission to use it for trade lectures here in Oz).
     
  8. Garry H (Cut Nut)
    Super_Ideal_Rock
    Trade

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    by Garry H (Cut Nut) » Dec 6, 2008
    http://www.hrd.be/uploads/media/General_information__English_.pdf
    http://www.hrd.be/uploads/media/Guideline.pdf
    http://www.hrd.be/uploads/media/Article1_H_A_objectively_measured.pdf
    http://www.hrd.be/uploads/media/Article2__Relation_H_A_and_cut_parameters.pdf
    http://www.hrd.be/uploads/media/Article3_H_A_Lighting_specs.pdf

    Paul these are all in the public domain and do not violate rights by opening them.

    But I hope that someone will write a consumer friendly explanation.

    I also hope Rhino will do a version explaining the attributes of diamonds with alternative patterns
     
  9. Paul-Antwerp
    Ideal_Rock
    Trade

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    by Paul-Antwerp » Dec 6, 2008
    I will need to check the Dutch HRD-texts in the office on Monday, but I have the impression that some important points are subject to a translation-error in English.

    At the presentation of this system, HRD promised me a demonstration of their machine. Since then, no reaction. I cannot possibly do you the favour of writing a review on Pricescope, without actually seeing it in operation.

    Live long,
     
  10. Garry H (Cut Nut)
    Super_Ideal_Rock
    Trade

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    by Garry H (Cut Nut) » Dec 6, 2008
    Paul it would be great to have a reiview of the dvice itself to determine if it is full programmed or if there is operator judgement involved.
    And translation of technical stuff can always be a problem - and I am sure with you mastery of both topic and langauge - it would be a breeze for you.

    But meantime what do you think of their standards?

    Brian might be able to comment too? Based on his understanding of the Japonese labs. I expect there is a close correlation owing to HRD / Japonese lab (forgot its name).
     
    


    


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