Hello, I have a bunch of Quartz & Topaz crystals from an alluvial deposit in a mixed parcel, & I would like to separate them in a quick & easy way... I thought of using a fluid with a density of 3gm/cm^3 so that the quartz float & the topaz sink... Which liquid is applicable for this purpose? It is preferred if the fluid could be made out of common material available at home! I high appreciate your contributions & thanks in advance.