For two years, Bunshaft searched for onyx. He even tried to get the stone during a revolt in French-controlled Algeria, which involved contacting the American ambassador in France to see if the French would send troops to access an onyx quarry. As he noted in a later interview “we eventually gave up on onyx.”
They decided to go for marble but even then Bunshaft had troubles. For example, marble from the quarries that provided stone for the Acropolis “looked characterless, like a lampshade,” and that wouldn’t do. Finally an old man from Vermont told him about marble from a quarry in Danby, Vermont. The stone wasn’t perfect. It was a “last, desperate thing…too strongly veined when you see sunlight coming through inside. It’s too yellow and black.” But it would do.
Each panel measures 54 x 54 inches and is 1.25 inches thick. Frames of light gray granite from Vermont hold the marble panes in place. The Danby marble is one of several varieties of Shelburne marble, which formed from metamorphism during the Early Ordovician Taconic Orogeny. Other trade names include Royal, Imperial, and Dorset.