Elsewhere, I've remarked on buildings going up in the city, noting that they're almost always faced in stone. I tried to describe the way these sheets of stone are attached to the concrete facade, and the metal fixture that makes it possible. I don't think I described it well.
Here's a picture of the metal bracing contraption that fixes the decorative stones to the facade. Several of these pins are inserted into holes drilled into each side of the stone, bracing it to the wall and to the stone adjacent to it.