Finding the density of a mineral is very easy, all you need is a triple beam balance and a water beaker. First you need to find the density, to do this you place your rock on the pan of the triple beam balance and slide around the sliders and once the pointer on the end is balanced thats your mass. To find the volume you put enough water in beaker that will fit the mineral and that has enough water in it to fully engoulf the mineral then put the mineral in the beaker and see how much the water level rised. Then divide your Mass by the volume.