This is actually very helpful for cutters JS. Thanks. From the point
of view of increasing understanding and in no way as criticism of
what you said I’m responding from what I see as a cutter. I am
replying point by point (in color) to further the understanding of
each other’s situations. I speak here only for myself, but I suspect
many cutters find ourselves in similar situations. Your statements
are in black mine in pink. In all the responses, I’m assuming a good
cutter. Many poor stones are obviously as a result of poor
workmanship. Those stones I would hope are also likely to be cheap.
I apologize in advance to people for whom this may be boring.
Very thin cabs. This is a problem for me especially when the cab is
large. Besides, I like the looks of a thick cab that sits more
proud in a bezel.
For me, if I cut a thin cab, it’s because that’s the only thing that
the rough allowed. It may be because that piece was slabbed by
someone else or the broken off sliver was thin to start with and
this is what’s left or there was a crack or other imperfection in
the stone that showed up only after cutting began. In fact, many
times interesting parts of stones are because of imperfections so
you’re going to be near them all the time. That means the useable
portion of the rough had to be pared down. I think most cutters
would prefer to do cabs of full thickness if they have the chance
but we only get to cut beginning with the rock we have since we can
only reduce from the whole. So if this rough seemed like a nice
interesting stone, it seemed better to have a thin cab rather than
just having to pitch it in the trash, especially after having done a
fair amount of work just to find out. In general I’ll try to salvage
what I’ve got. But there is almost always more waste than useable
material., unless you buy only high-graded rough, if that’s
available, One other possibility here was that the back of the cab
was a mess and cleaning that up has removed much material. Finally,
I think there is one basic misunderstanding here that metalsmiths
have about what stonecutters begin with. Now I’m speaking of cabbing
rough here. I’m guessing that when you’ve looked at rough at all,
you’ve probably seen nice even slabs laid out on a table. Those
require a large regular piece of rough to begin with. Most often
that’s just not the case. What cab cutters often start with is some
irregular piece of stuff that looks like a splintered rock you’d
kick on the ground. It can take a lot of time to recognize if there
is something in there worth saving, and to get to that point
sometimes we have to do quite a lot of work just to find out if
there is something cuttable.
Uneven doming so that the bezel has to be filed so irregularly.
(Although sometimes I like the look, it takes more time to get the
bezel right. I would say to the cutter to have doming even unless
the customer asks for it.)
This is probably from one of two reasons, the first is the
likelihood of poor cutting. The first question I’d want to ask is is
this cab a cheap piece? If so that’s why it’s so irregular. The
second possibility is that after having nearly completed the cab,
the cutter suddenly discovered a crack or other imperfection on an
edge. You grind that off, and what have you left? A well shaped cab
that has a different thickness on one edge. Reshaping that whole
thing will require practically recutting the entire stone. Now the
question arises, is the price you’ll likely to be getting for that
stone worth another hour more or less to recut and repolish?
Getting it back into balance is sometimes harder than cutting it
that way to begin with. “So what do I do with it now?” That is the
all too frequent question we have to ask ourselves.
Needle-sharp corners on soft stones--too easy to crumble when you
There is no good reason for this except lack of attention on the
part of the cutter. It would be good to know what would be ideal for
A slight bevel on the back edge to prevent chipping. It also sets
easier in the rare case where the solder left a little thick area
along the bezel if it didn't flow completely.
I think the back of the cab is the part of the process least
understood by setters. If you want to get more affordable stones,
here is the place you might save money. It’s important to understand
that cutting and polishing the back of the cab is about the same as
cutting and polishing the front. In fact it can be even a bit harder
because polishing a flat surface is more difficult and time
consuming than a dome. Also, as cutters when we are starting to work
a stone, we’re obviously taking the better side for the front. That
means there are frequently imperfections of various kinds on the
Now, in order to get this bevel you speak of, it’s going to be
necessary to redop the stone. If you try and do this bevel holding
the stone by hand, it’s unlikely to be even all the way around. The
dopping is done either with a form of shellac or wax which requires
heat, or with glue. The latter is better but takes time. Even
then, once you’ve got it dopped, because many people want a
perfectly finished back, as a cutter you’re going to spend quite a
lot of time working the back and trying to work around the
imperfections you were avoiding in the first place. I don’t know
about other cutters, but I find that polishing a part of the stone
that no one will ever see once it’s set feels like a waste of time
and certainly increases my cost of production. Of course there are
many stones in which the back will show, like anything translucent,
but there are very many in which it won’t. As I mentioned earlier,
there are imperfections of lots of kinds on the back. Those setters
who demand a perfect back on their cabs are often asking for far
more than they want to pay for. If you metalsmiths want to reduce
the price of your stones, and don’t mind imperfections which will
never be seen, you can get a great deal more. Also a slightly uneven
bevel on the back will save much time for the cutter too and I’m
talking about nothing that will be seen or affect the setting. You
can have a far better chance of getting the front of the stone that
does show at a much more reasonable price.
A very good polish.
A poor polish again, can be for at least two reasons. One is just
poor workmanship. Two is material that just refuses to take a good
polish. There are pieces that have soft spots etc that just won’t
polish well. But if the stone is interesting is it better to dump it
or try to sell it?
I like the cab to have at least a 1.5mm-2mm straight up edge before
doming begins. It's easier to form the bezel.
This again may have to do with the shape of the rough.
That’s if for me. I hope people will just skip this if they’re not
interested. And again I say thanks to JS for the insights. This is
what I had in mind when I started this.