Mosaic has always a dream hobby of mine! Anyone of you ladies can teach the subject, preferably with natural materials/stones/marble etc. as opposd to ceramic?
I have found supplies at dragon mart--go to the section that has tiling and such and ask around to the different shops if they sell tiles (I wish I could think of the name/location, but I can't recall it). Many of them will tell you no, but there are one or two shops that sell loose tiles.
Also you can order from http://www.mosaicartsupply.com/ They ship internationally and have GREAT prices (especially compared to the craft stores here. They ship internationally and I have used them several times! Their customer service is great as well.
Good luck!