Exactly how these granulated pieces were made is uncertain. It is then brought to a bright red heat, which melts the gold into minute spheres, separated from each other by the charcoal. When the crucible has cooled the charcoal is washed away and the grains remain.
Molten gold is poured into water from a height of several feet.
Whichever of these methods was used, the result was hundreds of very small golden spheres. The Roman jewelers next stop was sorting the grains by size. Sometimes the grains are attached to a metal surface by soldering. Often an intermediate work surface is established and then the grains are used. In this process first the surface, either stone or metal, is engraved with the desired pattern.