nothing much different from any other stone apart from make sure the sealer is for honed/polished stone.....dont know whether you know this but when using ditra.. you use appropriate adhesive for substrate to stick it down with.. then only use normal thin set adhesive to tile onto the matt...schluter do not advise using modified adhesives on ditra........dave.....
any info you need is in the schluter installation manual.........here's a link for you to download the manual.....dave...
http://www.schluter.com/media/brochu...ra_us_2007.pdf