"Rainbow Rock"- the detail with the perspective on the side facing away is a nice touch. If only the same care had been put into making the gradient more organic. plus a small, selective color palate is much more attractive than an easy rainbow.
Gold from Round Mountain mine, Nye County, Nevada, Southwest USA. The small piece of quartz is host to what at first appear to be wires until you closer and see that each wire is an elongated spinel law twin small cubes!