Almost any object can be used for rotating on the path of a logarithmic spiral. I start this example with a cube in two orientations. First with each cube separated by 10 degrees.
When each cube is separated by only 1 degree, the resulting structures appear pretty smooth.
While these structures do not look very natural, here are some more natural shells formed from distorted spheres.
When using blobs for constructing such structures, it is possible to decorate the outside with various details: