Sorry, here is the picture.

It looks like an onyx mosaic - could that be?

The walls could be onyx mosaic, but you are looking for the vanity tile...

It looks like a clay tile --maybe Saltillo? I'm not sure how that'd hold up on a vanity. (I am just not sure--have no idea). It is used a lot in Mexican/SW inspired kitchens on the floor though... It is just too porous, I would think,for a bathroom. So maybe you need to look for a saltillo-look ceramic?

Here is a link that might be useful: about saltillo

Maybe something like this?

Or google saltillo look ceramic or terracotta look ceramic tile

Here is a link that might be useful: saltillo look