Aqua terra jasper dried out

A few months ago I bought some Aqua Terra Jasper large pillow shaped
beads and cabs because I fell in love with the color and veining.
I’ve since found out that Aqua Terra Jasper is just another name for
soft onyx marble. My problem is that while I stored these stones in
zip bags, I have recently noticed that they look like they’ve got
dried out cracks and the rounded corners appear dry looking and
almost as if they’d been chipped.

Help!!! How can get these back to looking the way they looked when I
bought them and how can I use them in finished pieces? What do I tell
my customer about how to care for them so this doesn’t happen again?

Michele