Imported Models become puffy

I’m new to Unity, and for an early project, I am making a simple scene with some basic Octahedrons that I’m looking to build my world with (Octahedrons tessellate, so it ends up looking fairly interesting). I built my octahedrons in blender, and they were looking perfect. They were nice and sharp.

I imported them into Unity, but they ended up looking puffy. I joined a bunch of my octahedrons into a larger landmass to make sure that everything is flat and connected in blender, but in unity, each individual octahedron looks puffy, almost like bubble wrap.

Its not a big problem, its just annoying. I figure it has something to do with my lighting options, but I just hadn’t had time to mess with it. I suspect its a simple fix, I’m just not experienced enough to be able to notice what I did.

EDIT: The left of the picture is what my mesh looks like on the left; it is just two groups of octahedrons. The right is it with Unity. I know the soil texture oddly enough looks too muddy on the right side, but I’ll tweak that later.

At the object’s import settings:
alt text

Try setting both Normals and tangents to Calculate.