Coins last a very long time. A 2000 year old Roman coin could be lost by a Spaniard in the new world in the 16th century. The strike date only provides an upper

Coins last a very long time. A 2000 year old Roman coin could be lost by a Spaniard in the new world in the 16th century. The strike date only provides an upper bound on how long ago the coin was placed. The lower bound is the present.