As (Roman coin) as, the (2), (2), . After the as had been issued as a cast coin for about seventy years, and its weight had been reduced in several stages, a as was introduced (meaning that it weighed one-sixth of a pound). At about the same time a silver coin, the denarius, was also introduced. Earlier Roman silver coins had been struck on the Greek weight standards that facilitated their use in southern Italy and across the Adriatic, but all Roman coins were now on a Roman weight standard. The denarius, or 'tenner', was at first tariffed at ten asses, but in
Solidus (coin) permanently replaced the aureus. Constantine's solidus was struck at a rate of 72 to a Roman pound (of about 326.6 g) of pure gold; each coin weighed 24 Greco-Roman carats (189 mg each), or about 4.5 grams of gold per coin. By this time, the solidus was worth 275,000 increasingly debased denarii. With the exception of the early issues of Constantine the Great and the odd usurpers the solidus today is a much more affordable gold Roman coin to collect compared to the older aureus. Especially those of Valens Honorius and later Byzantine issues. The solidus was maintained essentially unaltered