From US Glass, this is a large mid-century Modern crystal vase. It was marketed under their Tiffin brand name as part of their "Swedish Modern" line, produced in the 1940s and 50s, consisting of large banded optic pieces inspired by Scandinavian designs of the 1930s. This example is a #6423 gladiola vase with the Manzoni foot, which is a hot-applied pad which is pulled out and curled into four scroll feet. It is illustrated in the 1951 Tiffin catalog.
It's 11.375" tall, 6.5" in diameter at the mouth and 4" square at the foot.
Condition: a few scratches and marks on the side, heavy wear to the bottoms of the feet. No chips or cracks.
Reference: Kelly O'Kane, "Tiffin Glassmasters: The Modern Years", p 79.
Item ID: 3678