An inscrolled or knurled foot. Sometimes also called "Spanish foot."

an inscrolled or knurled foot, sometimes called a "Spanish foot"

An inscrolled or knurled foot, also commonly called a Spanish foot.

The Braganza is a huge gemstone that may or may not be a diamond. This Portuguese stone is said to weigh 1680 carats (which would make it the largest-known diamond), but it has not been authenticated - it may actually be a clear topaz.