shape
carat
color
clarity

Cavity in diamond

Discussion in 'RockyTalky' started by Ashleigh, Dec 26, 2013.

  1. Ashleigh
    Brilliant_Rock

    Messages:
    723
    Joined:
    Nov 11, 2008
    by Ashleigh » Dec 26, 2013
    I noticed from browsing vintage and new diamonds that a higher proportion of vintage diamonds have cavity. Why is that so? I can understand vintage diamonds having chips and bruises due to wear and tear. I was under impression that cavity was already there during diamond cutting. But seeing so many vintage stones with cavity makes me wonder if cavity can be a result of wear and tear. Can anyone please help me? Many thanks ::)
     
    


    


  2. Ashleigh
    Brilliant_Rock

    Messages:
    723
    Joined:
    Nov 11, 2008
    by Ashleigh » Dec 27, 2013
    Anyone?
     
  3. Tourmaline
    Brilliant_Rock

    Messages:
    1,780
    Joined:
    Nov 17, 2013
    by Tourmaline » Jan 3, 2014
    Hi. My diamond has two cavities. They are naturals that were on the surface of the rough diamond, left to maximize the size of the finished diamond. They are really cool birthmarks, in my opinion.
     
  4. tyty333
    Super_Ideal_Rock

    Messages:
    20,484
    Joined:
    Dec 17, 2008
    by tyty333 » Jan 3, 2014
    I wonder if clarity was not such a big deal back then as it is today. That would be my guess.
     
    


    


  5. pyramid
    Ideal_Rock

    Messages:
    4,607
    Joined:
    Nov 10, 2002
    by pyramid » Jan 3, 2014
    It could be that Cut was not such a big deal then, so they were maximising the rough stones more.
     
  6. pyramid
    Ideal_Rock

    Messages:
    4,607
    Joined:
    Nov 10, 2002
    by pyramid » Jan 3, 2014
    Maybe one of the appraisers such as Dave Atlas or maybe Wink who is a long time vendor would know if there is a reason?
     
  7. Ashleigh
    Brilliant_Rock

    Messages:
    723
    Joined:
    Nov 11, 2008
    by Ashleigh » Jan 3, 2014
    Tourmaline, I'm confused. If yours are naturals, why did they become cavities?

    Ya, Pyramid, I think only the long time trade experts would know this. Wish they would see this question. I'm really curious.
     
  8. John Pollard
    Ideal_Rock
    Trade

    Messages:
    3,441
    Joined:
    May 1, 2008
    by John Pollard » Jan 6, 2014
    The short answer is yes, it certainly can be. Cavities occur when part of an existing feather breaks away, or when a surface-reaching crystal drops out, or is forced out. A cavity can occur during production or, if the potential exists, it can occur during a lifetime of wear-and-tear as you have intuited.

    Diamonds produced at the turn of the (previous) century barely had the advantage of the rotary saw. Bruting was often still - literally - the rubbing of two diamonds against one-another to create girdles. Polishing was rudimentary and done by feel. In those days there was little pre-evaluation of structural pitfalls or internal strain, meaning that finished diamonds had more potential for breakage than they do now.

    This is because today's production is extremely advanced. Planning stages reveal strain, cleavages, crystals, twinning wisps and other structural distortions. To offset such issues a diamond will be routed to a safer plan B or plan C. Mass-manufacture in a modern diamond factory now subjects every stone to hard-corps friction and pressure. From laser and rotary sawing to mechanical girdling and blocking, diamonds today undergo more stress during production than they did in previous eras. Once finished they have run an intense gamut that they will never again see in normal wear and tear.

    The bottom line: Finished diamonds today are more durable than some of their their decades-ago-counterparts - just as today's cars are safer and more efficient than early automobiles.
     
  9. Ashleigh
    Brilliant_Rock

    Messages:
    723
    Joined:
    Nov 11, 2008
    by Ashleigh » Jan 6, 2014

    Wow, John, thanks for the detailed explanation. :appl: It's very helpful. One question - If a cutter recuts a vintage diamond, would that diamond be subjected to that same stress during production, or would that old stone be routed plan B or C after pre-screening?
     
  10. Ashleigh
    Brilliant_Rock

    Messages:
    723
    Joined:
    Nov 11, 2008
    by Ashleigh » Jan 6, 2014

    Wow, John, thanks for the detailed explanation. :appl: It's very helpful. One question - If a cutter recuts a vintage diamond, would that diamond be subjected to that same stress during production, or would that old stone be routed plan B or C after pre-screening?
     
    


    


  11. John Pollard
    Ideal_Rock
    Trade

    Messages:
    3,441
    Joined:
    May 1, 2008
    by John Pollard » Jan 6, 2014
    Any diamond should be assessed by a knowledgeable re-cutter prior to any work. If feathers, naturals, crystals, strain, treatments (etc) are involved they must be considered. There is always some risk when putting a diamond on the wheel.

    This is where recut-repair is like an operating room. Some teams function like the Mayo clinic. Others resemble an Army field hospital. The best teams do excruciatingly thorough intake analysis, estimating safe paths and options with careful verification by several specialists. In other operations a single repairman makes a cursory examination, decides what he thinks is possible and goes forward without the same level of scrutiny and care, and with less options presented.
     
  12. Ashleigh
    Brilliant_Rock

    Messages:
    723
    Joined:
    Nov 11, 2008
    by Ashleigh » Jan 6, 2014
    Thanks for the sharing, John. :))
     

Share This Page