Australian Facetors' Guild Limited

Faceting the crown first.

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  • 30 May 2019 5:21 PM
    Reply # 7498288 on 6985463

    Thanks John.

    Something I forgot to attach to one of my posts about cutting this stone is the advice given with the cutting instructions, which are below.

     

    “Five Star Cut USFG SSC Master Class Design by Robert Strickland Test cut by Homer Barrs                                                              

     This is an easy, doable design for the Master class in this competition.  Most of you have your set of procedures to cut and polish your gems which you have developed over time.  Here are my thoughts and how I took on this one.

     

    I found this stone to be a very enjoyable cut, after several attempts.  What worked best for me was to do the girdle facets first.  Then instead of starting with the pavilion facets, I cut the crown facets first.  I cut all of the crown facets with one lap before going on to the next lap.  This way I made sure that I could get  all of the meets and angles done right.  Once I finished with the crown, I proceeded to the pavilion facets.  I was able to meet all of the size and meet point requirements this way.”

     

    Cutting the crown first was very good advice because I would have stuffed the stone up doing it in the traditional way. Usually it does not matter if the angles of the facets are not precise, as long as the facets are of equal size around the stone. But with those five stars it matters a lot, because the angle alters the size of each part of the star and they should all be the same. 1200 grit is the finest of my bonded laps and I recut the crown three times to get them looking right.


  • 31 May 2019 7:15 AM
    Reply # 7511772 on 6985463

    Hi Frank,

    It looks great.  The reflections from the surrounding colours give us an appreciation of the complexity of the crown.  

    Hope you do well.

    Are you going to enter the International Faceting Challenge?

    Regards

    Gordon 

  • 31 May 2019 7:48 AM
    Reply # 7512262 on 6985463

    That is a nice nice looking gem, Frank. And I, also, hope you do well in the comp. I’m nowhere near this level so it’s nice to see what you comp cutters are able to achieve.

    Terry

  • 31 May 2019 6:12 PM
    Reply # 7522153 on 6985463

    Thanks for the responses guys.

     

    Yes I will be entering the IFC for the first time Gordon. Not expecting to get anywhere though, but I enjoy the challenge of competition cutting.

     

    Frank.


  • 01 Jun 2019 9:13 AM
    Reply # 7533616 on 6985463

    I guess it is a case of "whatever works best".  However I am interested to know what was the norm when the Guild was first formed?  What drove the change to cutting the pavilion facets first?  Is it a matter of best light return from the pavilion facets or best appearance of the crown facets?  Maybe judging rules had a role?

  • 01 Jun 2019 7:34 PM
    Reply # 7543187 on 6985463

    Hi Bruce,


    I suspect it was a consequence of the work by Long and Steele on meetpoint faceting.  Once you start cutting to a pcp or tcp, cutting the pavillion first allows you to maximise the size of the stone.  

    Cuttimgthe crown first means that you would need close to twice the height you need to cut the pavillion first, a great deal of the material needed for the TCP would be ground away when the table is cut.

    Regardss 

    Gordon 

  • 05 Jun 2019 12:27 PM
    Reply # 7556400 on 6985463
    Anonymous member (Administrator)

    The best reason for cutting the pavilion first is to maintain performance - if you run short of material you can drop the crown height without too much loss, but if you drop the pavilion angles you may well have major problems. When cutting natural materials with flaws, you often encounter such problems.

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