Opus reticulatum

Opus reticulatum (also known as reticulated work) is a form of brickwork used in ancient Roman architecture. It consists of diamond-shaped bricks of tuff, referred to as "cubilia", placed around a core of "opus caementicium".
Name.
"Reticulatum" is the Latin term for "net-like", and "opus", the term for a work of art, so the term translates to "net work". The diamond-shaped tufa blocks were placed with the pointed ends into the cement core at an angle of roughly 45 degrees, so the square bases formed a diagonal pattern, and the pattern of mortar lines resembled a net. The initial, rough form of "opus reticulatum", an advancement from "opus incertum", is called "opus quasi reticulatum".
Uses.
This construction technique was used from the beginning of the 1st century BC, and remained very common until "opus latericium", a different form of brickwork, became more common. Examples have even been found in Etruscan cities, such as Rusellae, wherein opus reticulatum is present around the entire perimeter of the Roman amphitheater. As worded by Michael Blömer:
"Opus reticulatum "was used as a technique in the Renaissance Palazzo Rucellai in Florence, the skill having been lost with the end of the Roman Empire, and rediscovered by means of archeology by Leon Battista Alberti.