This coins error " where acid was struct around the side of the coin it shows AC1D the 1 being very faint" The DNA Double Helix 2-Pound Coin from 2003 is a valuable and unique piece of British currency. this coin celebrates the 50th anniversary of the discovery of DNA's double helix structure. With a denomination of two pounds and sourced from Great Britain, this coin is a symbol of scientific achievement and a prized addition to any coin collection.