The records where the coin is struck what mint. who supply the metal or flan, the distance between the  mint, the master die where it is located,the metal composition,the finished of the coin brozed or bronze,change in color or toning?,the average weigth,how many high grade coin in hands of collector when was the last time it goes out in the market. the boundaries when was the last production of a certain coin and year and what mint produce them. just a comment