I am preaty sure I have looked at enough rock in my life! I have been to the Tundra and seen real arctic rock, it looks very alike! The white lines are stains, they are found all over arctic rock.
It may not be the best but that comes with weathering.
It's a vast improvement from the old "uncompleted building" look the exhibit had, this gallery has some old pics of what it used to look like. I prefer natural rock as much as the neck person, but with some weathering, it should look better.
