Hexagon

Amethyst experiments

So once things were more or less caught up after Tucson, it was time for additional experiments with concave and fantasy variations.  First up is a 12.0 mm., 5.24 carat amethyst pentagon where concave facets were used for every other pavilion facet reaching the culet.

Next is this hexagon shaped amethyst which is 12.31 carats and is 14.5 mm. across. Similar to what was done with the pentagon,  this one has every other culet facet done as concave rather than flat facets.

The third amethyst in this group is 14.0 mm. across and weights 13.47 carats.  The concave facets were placed on the pavilion corners and as the center culet facets.

Then, for fun, a series of four round amethysts ranging in size from the 8.79 carat, 13.6 mm. one pictured above down to an 8.9mm., 2.58 carat version.  The culet facets of the pavilion were done as concave facets.  The diameter of the mandrel used for these was adjusted as the diameter of the stone changed.  Then for the crown, instead of the usual series of flat (or concave) facets, it was done as a single ring .

 

 

 

Yes, More Hexagons

Before I went off February 1st for ten wonderful days in Tucson, I was trying some variations to better understand how different facet placements would impact the resulting gem.  While there are software programs that will attempt to do that for flat facets, concave facets and fantasy variations are not included.  So I set up several stones and cut them with the same flat facet pattern but differences with the fantasy machine cuts. (Besides, faceting is more fun that sitting at the keyboard.)

The first one is a 12.61 carat lemon citrine which has all of the pavilion row of facets done with the regular mandrels for concave work.  It is 14.6 mm. across, so I managed to work in more facets than I have been using in some of the smaller hexagons.

 

Using that same flat facet arrangement, I did two somewhat smaller amethysts.  For one, a 6.60 carat, 12.8 mm. stone when done, I used a rounded fantasy wheel and made some small curved cuts.  These added some “lights” which seem to be inside the stone.

 

On the other amethyst, which finished at 5.65 carats, 11.2 mm., I added a lot more of these compound concave “facets”.  It looks like the stone is full of glitter.

 

For a totally different variation, after returning from Tucson, I tried something along the lines of the demonstration done at the USFG seminar on Fantasy cutting.  For this one, which is 5.40 carats and 11.0 mm. across,  I used a slitter and cut grooves from the culet most of the length of the corner facets.  These were left unpolished and they are reflected by the other facets to give the appearance of having many more grooves than were actually created.

 

 

More From Faceting Demonstrations

Pictured below are a few more stones started at a local club show as part of a faceting demonstration, and then eventually finished at home later.  The previous set was from the show by the club to our north, so these are from the show put on by the club to the south.

The first is a 9.81 cts. lemon citrine that is 12.4 mm. across.

Next is a 6.12 cts. prasiolite quartz 11.6 mm. round.  For this one, the crown was shaped into a dome before a few flat facets were placed on it.

And of course, I had to include hexagons.  This lemon quartz gem is 12.2 mm. wide and weighs 7.16 cts.

This is another citrine at the other end of the color range. It is 2.39 cts. and 8.6 mm. across.

All of these gems have concave facets on the pavilion so really sparkle.  And they are all from rough material obtained in February during my Tucson adventures.

 

Did I mention that I liked hexagon shaped gems?

Did I mention that I liked hexagon shaped gems?

These were started as part of the faceting demonstration at a local rock show and then provided a base for learning more about using some other tools on the fantasy machine.

4.48 ct. smoky quartz, 10.2 mm. concave facets on pavilion and apex crown.

 

lemon citrine, 6.69 cts., 12.1 mm, compound concaves on pavilion with the slitter tool

 

5.13 cts., smoky quartz, 10.8 mm., similar to previous using slitter tool to make small compound concaves on pavilion

 

one third of the way

Here is the first stone cut using the new fantasy machine. It is a 12.1 mm., 7.11 carat rose quartz hexagon with concave facets on both pavilion and crown.

For faceting demonstrations at the local club shows, I typically want something that is big enough for visitors to see, but inexpensive enough that I won’t be upset when working in less than ideal conditions (distractions!) results in mistakes. Lemon citrine and rose quartz seem to be what I end of choosing for these situations.

Since I had a number of pieces of rose quartz pre-formed from a chunk I acquired for just that purpose last year from Steve Ulatowski / New Era Gems, I am working with that for the “learning experiences” I know I am going to have getting used to new equipment and cutting options. It was a good choice — on this piece I had several “oops” happenings ranging from rolling off the mandrel (had it turning the wrong way) to running off the end of the mandrel (did not check the mast position adequately).