A small block of stone, tile, glass, or other material used in the construction of a mosaic. The artist carefully placed each tessera to create a stunning mosaic on the floor.
A token or ticket used in ancient Rome, often as a means of identification or for admission to events. The tessera allowed the bearer entry to the exclusive gladiator games in the Roman arena.
In planetary geology, a region of intersecting ridge and trough terrain on the surface of Venus, forming a tile-like pattern. Radar images revealed extensive tessera that hinted at a complex tectonic history for Venus.
Entomology: a small square or rectangular spot or marking on the wing of an insect. The moth can be recognised by the dark tessera on the forewings.