A very good photo from James Vance (his blog is linked at the end) of tesserae from one of the mosaics at Ostia Antica in Italy. It shows just how deep some of these tesserae were.
The questions I feel this brings up are;
Seeing as you can have relatively thin marble tesserae for a floor then what dictated the size of tesserae? Was it;
1. The area they were in, i.e. high foot traffic, private rooms?
2. The size of slabs/tiles they were cut from?
3. The preference of the mosaicists?
I don’t imagine there is a database of tesserae thickness with the above points taken account of but it would be useful to have these details recorded. If anyone has the opportunity to record the details (measurements and point 1 above) then please could you send them onto me, thanks.
Image copyright James Vance