The Rare Phase Search (RPS) technique is used for the characterisation of minerals present at less than 0.01% by volume, especially those present at levels as little as 0.1 ppm (0.00001%). For these minerals, such as gold, silver or PGM's, the number of occurrences on the polished surface of one 30 mm diameter grain mount is so few that quantitative mineralogical data cannot be prepared with useful statistical meaning. However, high-resolution electron microscope images of each rare phase occurrence can be very useful in a qualitative understanding of the deportment of that mineral. The report summarises the number of gold grains found, the relative abundances of each type of rare phase (e.g. electrum, tellurides), the grain size distributions and the modes of occurrence of the rare phases. High-resolution images are also supplied. Samples at the lowest end of the concentration range may report occurrences at less than one grain per mount. For example, a 0.2 ppm gold tail reported four occurrences of gold over 16 particle mounts in which there were many millions of particles searched altogether.
Sample Requirements:
Un-sized or sized samples are suitable. Requires 2-100 g.