As far as I can remember clam nuclei are on the whole "whiter", but are also more brittle than Mississippi mussel nuclei. They are also denser which doesn't make for a good fit at all when you consider the oyster.Originally Posted by julianner
When you combine these two features it doesn't make an attractive opition for the farmer. Even if the "whiter" calm based nuclei are less expensive.
Also if I remeber correctly the salt water clam shell can't be tumbled into a sphere as readily as the Mississippi mussel's shell.
While I've heard of nuclei being produced in China which look similar to those produced in the US, I can't say I know much about them.I am attaching a photo of shell nucleii that were used on the farm I visited. Any comments about whether they are clam shell or Mississippi would be appreciated by more than just me, I'm sure.
I'll also say that I have had pearls drilled that I bought from that farm and they've been fine.
Note, the pic shows a plastic bag of nucleii in the background and a few loose ones in my hand.
Though I know farms in FP (and other areas) that used 3rd grade Mississippi nuclei, it didn't effect the look of their pearls.
I dare say that a lot of farms that produce south seas pearls could also use them (second / third grade US produced nuclei), given the thickness of nacre that would be laid down over a 2 year grow out period. Though I can't say I've heard of any that do. Well not for the first pearl the oyster produces at any rate.