Polishing MOP?

[Pearly Shell]

I have a few old P. Margaritifera shells and am looking for any advice on how best to clean the up for display.

Would anyone have any suggestions on how to polish Mother of Pearl?

[J Marcus]

My suggestion would be to do it with a lapidary grinding unit--one with a good water-drip/wet-sanding function. It's not a good idea to breath the dust. Also, wear rubber gloves. The shell powder that grinds off of them is absolutely hell on your hands when it dries--it sucks all the oil out of your skin and can leave it dried out, cracking and bleeding! With shells the size of the P. Margaritafera you will find that an 8 inch wheel unit will work better than a 6 inch. Grind the outside of the shell with about 100 to 150 grit to start, then go to about 220 and then 400 or, even better, 600. Keep a spray bottle full of water at hand because the fine shell particles will clog the grit. Spray the wheels from close up every little bit to clean the grinding or sanding wheels. After the finest grit, you can use a buffing unit with stiched, soft-cotton, buffing wheels. Start with bobbing compound--there's a yellow kind (Goldstar?) that I especially like. After all the grinding marks are buffed out then proceed to another buff using Fab-u-luster for a final, mirror finish. Never buff or grind with an edge pushing up into the direction the wheel is coming from. It can catch and cause breakage or even injury to you. Also--no loose hair, ties or any other loose fabric attached to your body should get within yards (or at least a distance of twice their length or more) of the wheels!!. People have had their necks broken catching such things in the wheel. Really--not joking!!! Most of your grinding/polishing will be on the outside of the shells. The insides rarely need much finish work. If you buff the inside use a smaller--about 4 inch or less--buff and rotate the shell rather than try to buff from the top edge. (See warning above.) As a general rule, you are buffing or grinding more safely if you feel the wheel trying to pull the item from you rather than pushing it towards you or down. You can generally remove any polish remaining on the shell with a clean, soft cloth or by washing with a good detergent.

Would you happen to have any "extra" or "surplus" shells that you might part with for a reasonable price?

[Pearly Shell]

Thank you Marcus! This is great information. I can't wait to start working on these shells, they are souvenirs from an amazing trip to the South Pacific.

[GemGeek]

Yeah, there might be a few of us here that also have some crusty, but loveable souvenirs...

[Josh]

Wow Marcus! Great, comprehensive advice.
If your MOP shell is already polished and just dull from getting banged around, you can take the lazy route too and just do it with wet sand paper by hand. Progressively down to 600 grit should be fine.

[Mikeyy]

What ever you do don't breath the crap.

[Josh]

I've heard it's carcinogenic. Can anyone confirm? A good reason to use the wet sand paper too.

[Mikeyy]

I've heard it's carcinogenic. Can anyone confirm? A good reason to use the wet sand paper too.

I can't. I have heard of people getting ill from the dust. In fact they installed vacuums at all the machines in the shell factories in recent years. I don't know what there would be about a shell that would be a carcinogen. But what do I know. Every other day they say ______ will kill us.

[waimeamomi]

Wow, you guys have happy and uplifting posts late at night.

[Mikeyy]

Hey, Ya gotta die of something.

[waimeamomi]

Right, it might as well be pearl related. You must still be on Hong Kong time.

[Mikeyy]

I'm suffering reverse jet lag. Maybe I just need Geritol. Some of us old guys need it they say.

[waimeamomi]

Old guys? Not in my vocabulary.

[J Marcus]

I've heard it's carcinogenic. Can anyone confirm? A good reason to use the wet sand paper too.

I heard that as well and about a year ago I did a very extensive Google search on the subject. Although there were a lot of sites, medical and otherwise that said one should avoid breathing the dust of abalone and other shells, I was unable to find anything legitimate about it's being toxic or carcinogenic. Some of the non-medical sites made dire warnings about it but had nothing to substantiate their claims. There was, if I remember right, some concern among the medical community about the conchiolin in the dust. It is apparently made up of a complex mix of proteins that could, at least hypothetically, cause an allergic reaction--possibly, as they sometimes though rarely are--quite serious. In any case, Our lungs were made only for the processing of air and such dust can do them no good so I think it is best to avoid breathing the dust. Wet sanding, breathing masks and/or air filtration systems are in order.

[Pearly Shell]

It sounds like the warnings we have been given about breathing in dust from preparing cuttlefish bones for casting. Fine particles of calcium carbonate will collect in your lungs and diminish your capacity to breath. Not what I had in mind.

My shells are straight from the farm and I was just wanting to brighten up the inside of the shells. I happen to have some fabulustre and was going to try using that with my foredom. I think I might clean up the edges of the shell with a grider too. I have a dust mask, but think I will invest in a good breathing mask.

Thanks again for the advice!!