Georg Jensen Sterling Silver "Mobius" Large Brooch No. 374 by Vivianna Torun.
An iconic design that is beautifully sculptural.
This is a vintage piece from the 1970's that is in excellent condition. Handmade with a beautiful soft patina.
A similar example can be seen in the book, GEORG JENSEN JEWELRY by Isabelle Anscombe, Yale University Press, pg. 279.