Borax Cone - When mixed with water using the borax dish this forms a flux used during the soldering of gold or silver. The cone of borax is used with the flat bottomed borax dish by adding a little water and rubbing the bottom of the cone in a circular motion in the dish. The cone will dry out after use and can be used time and time again, eventually producing enough flux for thousands of joints.  
85gms Borax cone