I hate the tiles at the UN.

[ghostsinthemachine]

4. Bookmarking

Where the veins in each tile are aligned to make it all look like one continuous piece, or a solid slab. Or the face of the rock mined at the quarry.
On larger projects the pieces are marked at the quarry then laid so the veins are continuous. Most State Capitol buildings have great examples of this craft. I learned about it working during the restoration project at the CA state capitol which has miles of incredible bookmarked marble panels.