Marianne Ostier was born in 1902 and opened Ostier, Inc. with her husband, Oliver Ostier. She studied at the Vienna Academy of Arts and Crafts and was a practicing painter and sculptor when she fell in love with Otto Oesterreicher (Oliver Ostier) a third-generation court jeweler in Austria. They married and together they came to the U.S. in 1938 fleeing the Nazi's annexation of Austria. This is when they opened their jewelry business together under their new name Ostier. In 1966 Ostier’s jewelry appeared alongside Salvador Dali’s jewels at a special exhibition at Finch College of Art titled Art in Precious Jewels. Most, but not all, of her pieces are marked MO or M.OSTIER and some of her larger pieces have her entire name spelled out.