Forums General Discussion 2018 Single Stone Competition Questions/Comments

23 replies, 15 voices Last updated by flfaceter73 5 years, 1 month ago
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    Alan Balmer

    Jeff, we’re currently talking to our webmaster about updating the competition page.

    Michael, that’s an interesting question! I don’t see anything in the rules that precludes an opaque stone.



    Page 38 of the March 2018 Newsletter has Comments on the Yggdrasil, by Tom Mitchell.

    I just finished my first attempt on this using some citrine glass and although I will need to do it now with a better quality rough for the single stone 2018 competition.
    As stated… “The areas that may pose the most challenge”
    I didn’t have an issue with the pavilion facets and they polished nicely. I did have the table alignment problem because of the C3 table facets because of the low 8.38 angle. As you can see by the posted picture… In order to make a nice gem although not to contest specification I needed to over cut the table to get a symmetric alignment. Frankly I wasn’t paying attention to the comments until after the fact so you guys and gals who haven’t started your single stone… pay attention or you too will be doing it over again. 🙂

    Bert Webb
    Sophia, N.C.

    You must be logged in to view attached files.


    I was wondering the same thing about the Grand Master material (entering an opaque stone). The design (page 44 in the newsletter) has a Material list: “Feldspar (Moonstone, Orthoclase, Labradorite, Plagioclase from Madagascar). Not sure why Madagascar plagioclase is so specific, maybe orthoclase? I have never seen a clear or even translucent Labradorite (which is a type of Plagioclase feldpar). Labradorite is one of my favorites and would be a nice looking opaque stone if it weren’t for the extensive coarse texture banding, cleavage steps and cracks. Hard to find a specimen that would be worthy of entry. I bet it would also be hard to judge with all the labradorescence flash and texture. I might just cut one for the heck of it for a practice piece. Could we get some official clarification on the entry of an opaque stone? Seems counter intuitive for a Grand Master entry.


    Alan Balmer

    OK, the official word (and a warning) on opaque stones, from our head judge:

    There is nothing in the rules that says that the stone being cut has to be a top quality gem. The judging process does not concern itself with the interior of the stone. It only judges the quality of the cutting, the meet points, the facet edges, the polish and the dimensions. Therefore it should not be a problem if a contestant wants to submit an opaque stone. Word of warning though to the cutter: If a flaw in the stone breaks the surface of a facet it will result in a penalty. It is far easier to see flaws in a transparent or translucent stone than it is in an opaque stone.


    Aldrich, John
    @Double Eagle Mine

    To update possible feldspar for cutting. Oregon Copper Bearing Sunstone is also a Labradorite Feldspar and found in transparent gem quality.


    Alan Balmer

    The Single Stone Competition page has now been updated



    Thank you Alan Balmer. Somehow I missed these responses that have been posted since the middle of April. The caveat about an internal blemish raising its ugly head is well-received. For the Master category I am working towards this year the required material is C.Z. so basically not an issue but it has been something I have been wondering for the past couple of years.



    Looks like the judging is done and the stones are on the way back to the cutters. Mine, and a friends, both arrived today.



    Thanks for letting us know that.

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