There are infinitely many dissimilar icosahedrons, some of which have more symmetries, others less. The most famous (convex, non-stellated) regular icosahedron is one of the regular polyhedra, the faces of which are 20 regular triangles. (Wikipedia)

Firstle I created platonic and done a bevel deformer. 

Then I created Volume bulder and Volume mesher and drag platonic under it. 

Also I createt Shader field with noice shading and Volume mesher subtract it from platonic. 

After I take a material and render it.

ArtStation: https://www.artstation.com/marden

Wikipedia: https://en.wikipedia.org/wiki/Icosahedron