The platonic solids are special polyhedra -- each side is made of a regular polygon (i.e. the length of all sides are the same) and they are the only five such polyhedra that can be inscribed within a sphere so that every point lies on that sphere.
The pack contains:
Tetrahedron:
1 prim, 4 faces. This is actually just a regular "prism" prim. It's included just for completeness and the proportions are conveniently preset to be accurate. (FYI, the x,y,z proportions are 1:1:.75)
Cube:
1 prim, 6 faces. Yeah, nothing special about this one either. Again, just there for sake of completeness
Octahedron:
1 sculpted prim, 8 faces.
Dodecahedron:
1 sculpted prim, 12 faces.
Icosahedron:
1 sculpted prim, 20 faces.
These sculpted prims are the special items -- they've been carefully constructed pixel by pixel so that the points and edges are crisp and well defined and so that they *remain so* regardless of the prim size and as distance they're being viewed from. These shapes will only smooth out from quite far away (and with the exception of the back side of the icosahedron which smooths out faster -- what can I say? There are unfortunately some technical limitations). Sadly that means sacrificing texture mapping quality a little, but as you can see, planar-mapped textures still work really well on these prims.
Lastly as an added bonus, there is a nice kinetic display sculpture included (17 prims). Touch each of the solids to start/stop them rotating individually; touch the base to start/stop the entire sculpture rotating.
If you'd like to use these shapes in your own products, trans/mod/copy Sculpt Maps are also available!. See this listing: Platonic Solid Sculpt Maps
You can see the Platonic Solids (and purchase both the solids and sculpt maps)in world at Cranston Lush Green.
See item in Second Life
