ive been given a problem in physics, its to prove if a lump of metal we have been given is real gold or not. one way to to do it would be to work out its density, which is fairly easy, mass/volume. (its not real gold by the way, we just have to show it). But as this is the route that all the other groups are gonna go down, id like to do something more interesting, but im not sure if its possible with the equipment, which consists of, basic optics equipment like a ray table, lasers,(which would give us a known frequency of light), prisms, mirrors, rheostats, transistors, geiger counters, thermometers, diffraction gratings, and a few other things. Maybe its also possible to measure some absorbtion(fraunhoffer) lines? does any body have any ideas or know problems that i might come into?