Commonly, it is portrayed as a large, twisting, horn-shaped container overflowing with produce, flowers, nuts, or wealth of some form.
The principle shape of the Cornucopia is that of The Golden Spiral.
The Golden Spiral is an example of a logarithmic, or growth, spiral which was first described by Descartes. Unlike an Archimedean spiral, in the logarithmic spiral the distances between the turnings increase, in geometric progression.
In the case of the Golden Spiral, the growth factor is Phi.