Aging travertine artificially

Aging travertine artificially Images

Aging travertine artificially

Aging travertine artificially Description

I understand (http://maplered.com) that travertine can be aged by dissolving it with some acid.  I am trying to duplicate the tumbled look of some Tiles (http://www.g682.net) I have that are labeled "noce" by my local supplier.  I cannot find any info on this doing a search.  Can anyone tell me how to do it?

thanks