Neither the calcite nor aragonite forms of calcium carbonate are poisonous but some animals assimilate high levels of various metals which are or can be poisonous. Since calcium carbonate readily dissolves in an acid environment, those metals tend to become readily available. Apparently, some persons are alergic to the proteinaceous portion of the nacre and have reactions to the dust - headache, nausea, etc. Dust supression by using water in all stages of the cutting and polishing processes will minimize both of those problems and latex gloves will keep the worker "mud-free". The water also keeps the material being cut from overheating and having opaque white spots form during grinding and polishing phases.

I had an interesting request for information today. Judith is allowing me to publish this to the list as I do not have a good answer for her and I do not remember this ever being discussed on the list before.

I recently read a comment on the chat list of the jewellery makers' website, ganoskin.com., stating that the abalone shell is a deadly one to cut or grind, due to the fact that the body absorbs the dust through the lungs or skin. The body then interprets this substance as a sugar and sends it to all the organs. There followed an anecdote about a group of people dying just a few months after beginning a new efficient process of cutting abalone shell. Pustules in the lungs, death due to pneumonia. It was also stated that the dust can be absorbed when suspended in a solution.

Do you know of any writings that go further into the subject of the toxicity of abalone shell?

I'm going to have to cut some of these shells in my work, and I must find a safe way to do it.

Thanks so much,
Judith