I was told that emerald cut stones cannot be flush set
Somebody told you wrong, then. Emerald cuts aren’t the easiest to
bezel or flush set, but I’ve done it countless times. Carving for a
flush set is a real challenge, if you haven’t done it before. This is
because you need such a very precise seat, since only the smallest
amount of metal will be moved laterally over the edge of the stone.
But, there’s a little trick you can do. Are you ready for this? It’s
going to take some heavy visualization.
First, consider making a design where you carve a seat for the stone
to sit in with the girdle just about even with the surface, and then
solder on a bezel of a soft metal like fine silver or 18 karat (no
18K white though, unless it’s palladium white, in fact, if you’re
doing it in white gold, why not use a pure palladium bezel?) An
inverted cone bur is great for making seats for emerald cuts.
But if you really want to do a flush set, here’s how.
First, call Rio Grande and order a can of “Seat Check”. It’s a spray
on powder that you apply in the seat you carve, press the stone down
into it, and it reveals, by changing color, where the stone is making
contact so you can clear out those areas.
Now to the carving.
Once you get the shape of wax you want, and you have the area you
are going to flush set into, use a tiny drop of super glue and glue
down the stone, upside down. Now carefully trace around it with a
needle. If the stone isn’t cut badly, it will have the same shape
upside down or rightside up. Hog out the seat with a round bur, then
go in and shape the cavity for the stone using inverted cone burs.
Now start using the seat check. You want the stone to sit evenly with
the girdle just about 1 millimeter below the surface. Less depth for
smaller stones. Once you are confident the stone fits, a smooth fit,
not requiring pressure but not rattling around, you’ll go to the next
Using a touch up wax like “perfect purple” or that new wax Kate Wolf
came up with (sorry Kate, can’t think of it off hand, pipe in if you
see this), build up a tiny ridge all the way around the stone. In
your case, I’d build it up about half a millimeter high and about
half a millimeter wide, like a tiny bezel around the stone. You’ll be
dabbing on wax, then using carving tools and burs to shape it, maybe
going back and adding wax, taking it off, etc.
When you’ve cast the piece, get out your Seat Check again and using
burs, inverted cones, round, whatever, clean the casting skin from
the seat and make sure the stone drops down in. Get the ring or
whatever article firmly mounted where you can hammer on it, either
jammed up on a ring mandrel (be careful of the culet!), or on your
GRS inside ring clamp, or using Jett Set or shellac and a vise,
whatever you’re accustomed to. Before you start to hammer that tiny
bezel down around the stone, take a small round bur and just under
the top of the bezel, inside, where the girdle of the stone will be,
cut a slight notch all the way around. This is so that when the
metal starts to move in around the stone, it doesn’t bind in on the
girdle before the top edge of the bezel comes down on the stone. Now
smear a little soft wax like disclosing wax, or bees wax mixed with
Vaseline, and gently warm the article till the wax runs in around the
stone and let that solidify. Wipe off the excess. Start hammering
with a chasing tool and hammer. Use enough magnification that you can
actually see the metal as it contacts the stone. You’ll see the wax
squeeze out around the stone. This makes it hard to tell what’s
happening, so go ahead in other areas. When wax is oozing out all
around the stone, steam it off. Now the stone will probably be
rattling in the setting, but you can continue to tighten down the
ridge. You’ll hear the pitch of the ringing of the tool on the metal
change as the metal makes contact with the stone, and that’s the time
to stop driving it down in that area.
Now to cleanup. Assuming you’re satisfied the stone is tight, you’ll
want to get a flat graver polished to a mirror finish, razor sharp.
Dull the leading corners very slightly against your sharpening stone.
Now you can go around the inside edge of the setting and create a
clean edge. Keep your sight right down on what you’re doing, it’s
easy to scratch a citrine, even with a graver that’s been given
dulled corners. Keep thumbs together for control. The last thing is
to dress down the surface, using sanding sticks or disks, but be very
careful not to hit that stone. You can cover the stone with masking
tape, but you still need to stay away from it with any steel tool or
abrasive. A flat lap charged with tripoli will finish the job, and
you won’t damage the stone as long as you down bear down on it and
your lap isn’t contaminated with anything gritty.
Well, best of luck, keep us posted.
David L. Huffman