Hi, they look like Little Diamond tiles from the Dwell collection by Heath Ceramics based in San Francisco. I know because I saw a picture of them and loved them and hunted them down! I even got them to quote for shipping to the UK but the cost was prohibitive for us sadly. If you're in the UK and find anything comparable, please let me know!

When you say 'practically new' how long are ypu actually talking? Tiles tend to have a shelf life with suppliers of 3 years or so. So you may struggle to get them again. However, you would need to start with the usual suspects such as Topps Tiles, B & Q, Wickes etc before moving onto specialist suppliers. Good luck!

Be prepared to take out a second mortgage to pay for them!!! I spent a wonderful afternoon browsing around Chelsea Design Centre. The Ann Sacks store is glorious and more than a tad on the pricy side ;-)

Hi they look like they are marble and possibly from Ca Pietra. http://www.capietra.com/shop/stone-walls-floors/jet-set-collection-milan/.  Happy hunting!