Without any caring for several decades, you may be shocked that natural gloss of pearl has gone. Due to the unsteady mineral aragonite, which is the main component of pearl, it will become common calcite and turns yellow gradually.

If the yellowing is still limited to the surface, we can adopt a method to recover its natural gloss.

Soakit in the 1%--5% diluted hydrochloric acid or hydrogen peroxide for a moment . Wait until the yellow shell has been dissolved and take pearl out quickly, wash and dry it and then you will find the aging skin is removed, and the glorious charming color comes back again.

Do remember do not soak it in the diluted hydrochloric acid for a long time so as to prevent the pearl from being destroyed.