Martha mine is a Silver beast and in a search I found these historic facts about the mine.
Historically theMartha mine, which is the largest within the extensive Hauraki ... 167.5 tonnes (5.4 Moz) ofgoldand 1050 tonnes (33.7 Moz) ofsilverfrom 12.2 ... The average Au:Agratiois 6.9, although within themineit varies from 6.2 to 11.2.
If the following you tube is accurate and the waihi area and wkrp has silver then the future IMHO is looking bright.