A key factor in the success of any geophysical survey is a knowledge of the physical properties of the rocks. Data from formations in the exploration area are needed to design the survey and to model the results. In epithermal gold/silver deposits contrasts in rock properties between host lithologies, and different alteration zones can be subtle. Maximising the benefit from geophysical surveys, and extending exploration into areas of cover, requires careful attention to rock properties (magnetisation, resistivity, density, and gamma-ray signature). CITATION: Kellett, R, Caratori Tontini, F, Turner, G and Bromley, C, 2019. Geophysical properties of rocks from the Hauraki Goldfield (New Zealand), supporting continued mineral exploration, in Proceedings PACRIM 2019, pp 145148 (The Australasian Institute of Mining and Metallurgy: Melbourne).