Wits End Mosaic - Another good mail order source for both traditional and more modern mosaic materials, tools, supplies, etc. Tabularasa - Another good mail order source for smalti, marble, and some very unique tools.
Small quantities are available for the individual artist.
Located in Rome, Italy. Nice people too. Check them out. Classical Mosaics - A new and developing site by a friend and colleague, Norman Tellis. Located in Texas, USA Anima Ceramic Design - A showcase of Lucinda Johnson's talented artistry using both handcrafted and decorated tiles and traditional mosaic material.