Could we "3D golf" to make coins looking the same, but using even less vertices?
Or you could reduce the texture complexity to a 2D texture without raytracing if you defined the coin mathematically in the shader. Heck, you could get rid of the texture entirely and just do everything with math in the shader.
3D graphics used to require rigid hardware distinctions between vertices and textures and etc, but in modern pipelines it's pretty much all data and the programmer decides what to do with it.