Mother of Pearl

It's brittle. It's often worked with jeweler's saws and abrasive sticks. I've used abrasive cloth and paper wrapped around wooden popsicle sticks, etc.

Watch out for the dust. It's highly toxic. Wear a tight-fitting dust mask when you work it.

I find it miserable to work, but jewelers who do a lot of it probably are more comfortable with the stuff.

What he said, except wear a respirator- powered if possible. Lots of shop filtration and ventilation, downdraft table with

------------- In Polynesia, artists use tungsten carbide burrs and high-speed handsets (30,000 - 60,000 rpm) to carve it, and diamond disks to cut it.

We were given a bunch of shell when we were in pearling areas. My wife has played with it and, while you can cut it with a jeweler's saw, the blades don't last long. A Dremel and diamond-coated steel disks work great. It's very brittle.

Polish the usual way; coarse stones down to rouge for the final polishing.

Kevin

Develop Windows(tm) Applications - in COBOL!

Quote "Watch out for the dust. It's highly toxic. Wear a tight-fitting dust mask when you work it."

Can you point to some data to support this?

Nope. 'Just repeating what I've read in several accounts of jewelry-making over the years. When I bought some for inlays around 20 years ago, the shipment contained a very scary letter describing the same caution.

Ed Huntress

Obviously, you shouldn't breathe dust of any type, but I have never heard of mother of pearl being toxic. Abalone shell however is toxic. I've done inlay work on guitars with both and have never had problems nor has anyone I have known who did this type of work. Keep in mind that we were only working with flat sheet cut to shape and polished. I did know a guy who almost died trying to grind abalone from raw shells. He later found out that this procedure is normally done under water.

Here is a URL for a site on working mother of pearl.

Kelley

From an arts safety website put up by the City of Tucson Environmental Management Division (?? I can't certify their accuracy):

"Fine shell dust irritating; mother of pearl dust causes fevers, pneumonia-like disease."

Thanks for the great replys and the web site. I now have a much better idea as to how to go about it. Thanks again, Rick

That is an old tale that is often repeated. I have even seen in print. MOP is made of around 85% calcium carbonate, (Same stuff in a Rolaids), 12% conchiolin,(A protien that acts as a binder) and 3% water, none of which are harmful or poisonous. You should not inhale any kind of dust in large amounts if you can help it, but the use of the term toxic creates images of having to ware protective clothing to be near the stuff, you could eat it if you like. It is often mixed into women's cosmetics. The stories seemed to have gotten started around the turn of the last century. People who worked with shells became sick and many even died. That was due to the bacteria contained in the unclean shells that were often many days old and being a once living thing now was seething with toxic bacteria. The toxins responsible for most shellfish poisonings are water-soluble, heat and acid-stable, and are not even inactivated by ordinary cooking methods. It is not surprising many of these people became sick. The clean MOP though is in no way toxic. I guess someone could have an allergic reaction but that would be unique to them. Simple precautions such as you would use with any dust is all that is needed. The body inhales pounds of foreign particles each year and in most all cases it just leaves with the next breath and the remainder is removed with mucus. If breathing in particles was such a danger, you could not ware a cotton shirt, bake a pie using flour or play with the kids on the floor. We are a pretty tough animal.

"Ed Huntress" wrote in message news:...

Thanks for debunking an obvious bit of folk mythology. People eat all kinds of really gross stuff and they would b worried about a little calcium dust? Wear a dust mask and for sure do not drive a car.

(rest deleted)

OK, not poisonous like rat poison or cyanide, but dangerous to work with nonetheless. Consider the dust that flakes off this stuff: look at it under a microscope, and you'll see little jagged spicules. Once they're in your lungs, they don't ever dissolve, or break down and get carried away - they just sit there and get scar tissue built up around them. Think asbestos from abalone.

The bottom line: don't breathe the dust. It's bad juju.

MOP and abalone shell get used a lot in lutherie, the art of instrument building. There are a bunch of lutherie sites with info on the dangers of MOP and how to contain them.

Alden

look at it

Spicules!?! Have you been reading Heikki Seppa?

Paul K. Dickman

Although, honestly this is good advice in general. Any process that generates finely divided airborn powder of *any* kind, metalic, non-metalic, organic, whatever, is something to think twice about.

Jim

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