Outer material of seashells

[Janet]

How do you remove the outer material of seashells, so the
mother-of-pearl is exposed? I put a shell into a vibratory tumbler
with ceramic balls and Sunsheen. After four hours, the outer layer
was unaffected (although the mother-of-pearl that was already
exposed is nice and clean now).

Janet

[Christine_Pyman]

Hello janet, the traditional way is to scrape with a specially
shaped knife, but you can also use a dilute solution of bleach,
experiment with dilution strengths first, becuase this method can
work very very quickly… rinse well, too. Have fun, Christine

[Janet]

    you can use a dilute solution of bleach 

Christine, You suggested bleach, others suggested CLR
(Calcium-Lime-Rust Remover). So I used both–not at the same
time!–bleach, then CLR, then bleach, then CLR. It worked great.
Thank you!

Janet