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Industry standard for calibrated cabs


#1

Hi,

I am a stone dealer specializing in larimar. I have been making
calibrated cabochons in oval and tear drop shapes in the following
sizes:

Ovals-28x21mm, 21x16, 14x10 and 11x8.
Teardrop-27x19mm, 22x16, 18x12, 12x9, 10x7.

These sizes were created based on my own customers’ wishes. My
question is: Is there an industry standard for calibrated cabochon
shapes and sizes? My fear is that I might be cutting cabs that are
in sizes that other people will not want.

Thanks for any advice you can give me!

Michael Rothstein, Reliable Larimar


#2
These sizes were created based on my own customers' wishes. My
question is: Is there an industry standard for calibrated cabochon
shapes and sizes? 

I think this from the International Gem Society is for faceted
stones, but I don’t know if cabs would be different.

No official sanction, as far as I know, but from a practical
standpoint, look at the Tripp’s charts here:

http://www.tripps.com/chart.htm

Al Balmer
Sun City, AZ


#3
Is there an industry standard for calibrated cabochon shapes and
sizes? 

Pretty much, Michael, yes. I don’t care what size a stone is,
because I make special order anyway - even if it’s calibrated it’s
still going to be custom made, almost always.

Where it matters is in production and also the amateur/less skilled
jewelry business. That’s where people are buying findings or
ready-made pieces and plugging calibrated stones into them. Meaning,
that’s where you should look. Stuller carries calibrated stones and
a few calibrated mountings (as they are mostly not cabochon based
jewelry). You can look without an account, you just won’t get prices

  • stuller.com. Rio Grande carries some pieces… One source is
    Paradise Wax Patterns

http://www.paradisewaxpatterns.com

I’m having trouble loading their TOC this morning, and it’s a chore
to navigate anyway, but they have lots of stuff. You’re not stealing
anything -those numbers are everywhere in the industry. Stuller’s
black onyx section has many sizes - some of the other stones don’t
go as large as you mention. Most of those are cut with calibrated
cab cutting machines, so it’s pretty standard all over…

http://www.donivanandmaggiora.com


#4
I think this from the International Gem Society is for faceted
stones, but I don't know if cabs would be different. 

Sorry, I omitted the URL for this:

Al Balmer
Sun City, AZ


#5

The “calibration” of stones (and associated settings?) depends on
who’s doing the calibrating. It’s something similar to ring size
depending on who’s doing the sizing (and which of their sizing tools
they use.). Some similarity in dimensions among different individuals
or organizations may occur, but that doesn’t necessarily imply
collaboration.

Mike DeBurgh, GJG
Alliance, OH


#6

Hey folks, we are talking cabs here right? Well, if you take a look
in any of the well known jeweler supply catalogs, you will find
ready made settings that follow very specific sizes and shapes.
Rounds, ovals, squares, crosses, teardrops, etc etc. They are all of
specific shapes and each will have a variety of sizes. Now go to a
lapidary catalog such as Graves Co. and they sell templates of
plastic or aluminum of the very same shapes and sizes. These
templates are used to draw the shapes onto the stone slabs prior to
cutting. A skilled lapidary can then cut exact shapes and sizes,
purchase the settings/findings and easily produce jewelry. Frankly, I
very rarely cut calibrated shapes!! The price of rough continues to
go up and, depending on the kind of stone, is becoming a burden. So,
I mostly cut freeforms that use the entire stone in the shape and
size Mother Nature gave it to me. Of course, then I must create some
setting to hold the stone. But that is not a difficult process and
allows for a great deal of innovation and artistic license. Cheers,
Don in SOFL.