This spinning disc of Nariño presents a radial symmetry just like all the very few ones found. Its geometric figures –different types of circles– are organised around the central orifice. With a piece of wood and two pins it would have been easy to trace a circle starting from a hole on a square sheet and then cut it into a perfectly round shape. Yet the eight motives distributed at the same distance required special mastery and even if you look at them very closely there is no evidence of the hypothetic pin.
This disc has two colours and it is not painted. Made of a copper alloy with very little gold, the surface was washed with acids to remove the copper already rusted and leave a layer of gold –acid resistant– just a few micras thick. This finish is known as depletion guilding or mise en couleur. The circles were drawn by scratching this delicate layer of gold to expose the pink copper colour of the inside, after they were rubbed slightly with a stone, from one side to the other, to produce the radial gleams. Such mastery and perfection is only overcome by one unusual event: the same motive is represented on the other face of the disc and both motives match, perfectly overlapping on each side of the object. EL