This thread discusses the Content article: Oh! Gold in Nabua!

I hope you'll get hold of Cheche Lazaro's documentary on the said gold exhibit in Ayala museum and it will answer your questions. As for the details on the gold unearthed in Nabua, maybe you'll find it in Ayala library which holds a wide range collections of Spanish colonization era documents/records. I heard their collection is far more better and more systematic than our National Archives. Ayala library is located in Bank of the Philippine Islands Headquarters, in Ayala Ave., corner Paseo de Roxas Makati city.