The floor itself is constructed from some kind of tiled mosaic. Kneeling to inspect, you find the patterns are made from a square grid of coloured marble. Quite how they obtained this marble is unclear, but there is no denying its existence.
A mixture of smells are in the atmosphere. The patch of mould is giving off a musty, ancient smell, not that of fresh, live bacteria. Also in the air is a faint tang of incense, and also some pot pourri derivative.
Warily moving closer, you peek inside the open urns around the tomb's base. One is filled with small flower pieces, and presumably giving off the pot pourri smell. One is filled with water, a thin film of dust coating the surface. One seems to be filled with silver coins. Further than that you cannot see.
It seems that you have a few options to investigate. Before you go about plundering the tomb itself, you can take a closer look at the murals, or have a better ganders in the pots and urns.
Zing - look at the wall patterns
Zing - look in the pots
Zing - head straight for the tomb