Barcelona Pavilion

Mies van der Rohe used four stones at the Barcelona Pavilion: Roman travertine underfoot and on the perimeter walls, green Tinian marble and Alpine Verde antico on free-standing screens, and a single book-matched slab of golden onyx at the heart of the composition.

The onyx is the lesson. Mies sized the entire ceiling height to a pair of matched onyx slabs, turning a material constraint into the building's proportional system. It remains the clearest built argument for treating stone slabs as the dimensional unit of a design, not the other way around.

Book-matched onyx and decorative marbles are still quarried in block sizes that permit this kind of feature-wall treatment. Early engagement with a supplier is essential: the slab dictates the detail.