I import a .STL
Import[*.st,"VertexData"] file on mathematica and I remark that the number of vertices is increased comparing to the number given by Blender. However, the number of polygons is the same in both cases.
here is an example of .stl file.
I am running mathematica 10.2 on Mac OS X.
The problem is do to Mathematica 10.2.0 on Mac OS X. I tried the same program on linux using Mathematica 10.0 and I get the right result. In addition I tried Mathematica 10.1.0.0 on Mac os x and it works correctly.