Srdjan M. Bulatovic, in Handbook of Flotation Reagents: Chemistry, Theory and Practice, 2010. 17.10 Flotation of Arsenical Gold Ores. There are two major groups of arsenical gold ores of economical value. These are the massive base metal sulphides with arsenical gold (i.e. the lead–zinc Olympias deposit, Greece) and arsenical gold ores without the presence of base metals.