Most Ancient civilisations produced coinage systems and today these ancient coins are sought after by coin collectors worldwide. - From ancient European civilizations, Roman, Spanish, Greece to Asia Ottoman Empire. Among the most sought after coins are Ancient coins from 3 periods - Roman Coins from 1500-2000 Years old - Greek coins from at least 2,000 years old - Byzantine Coins at least 1500 years old.
The early Roman coins made from brass ,copper or bronze had clearly defined denominations with a classification system as below
AE1 coins of 28 mm diameter or larger
AE2 coins between 23 and 27 mm diameter
AE3 coins between 18 and 22 mm diameter
AE4 coins 17mm diameter and under