How did the Romans make mosaic?

First the Romans used chicken oil the rub on the mosaic for good luck. Then put pieces together.

I'm not sure about the chicken oil, that's a new one on me.

The small tiles, known as tesserae were cut from stone using a set of tools called a hammer and hardie. The hardie is a small chisel set upside down in a block of wood and the hammer has a blade on it. The marble is held on the hardie then struck with the hammer. Mostly the tesserae were cut to about 8mm - 12mm pieces.

The pattern was scratched or painted onto the floor and then using a mix called Pozzolan as the cement they would trowel small amounts onto the pattern and place the tesserae in the cement.

The floors were then ground down and then polished/waxed.