Each mosaic tile is 5/8"--even smaller than my smallest quilt square.
I love Pottery Barn stuff, can you tell? Medicine cabinet, light fixture and train rack.
Oh, and look what is this? A nine-patch in the tile? This was actually the idea of the woman and the tile store, to take 3x3 mosaic fragments and place them in the upper part of the bath/shower area. Fitting I think.