The propensity of high voltage pulse (HVP) towards mineral-enriched ore particles during treatment has been reported by researchers at the Julius Kruttschnitt Mineral Research Centre. However, the fundamentals of HVP selective breakage between particles remains unclear due to complex mechanical and electrical properties of the natural ores. An experimental study of HVP selective breakage was conducted using fabricated synthetic particles embedded with various metalliferous minerals of different conductivities/permittivities. HVP tests were performed by placing the mineralised and the barren synthetic particles in the pulse discharge zone, which were then treated with one pulse loading. Part 1 of this study presents evidence of metalliferous grain-induced breakage in a two-particle paired system, with barren particles remaining intact. High-resolution images of the mineralised fragments showed that the electrical breakdown channel exerted detrimental effects upon the integrity of all the metalliferous grains tested, resulting in complete disintegration and heavy surface oxidation of the metalliferous grains, rather than liberating the metalliferous grain along its boundaries as reported in the literature. In addition, the influence of metalliferous grain locality in a particle on HVP breakage selectivity is also investigated.