Venera (Spanish for "scollop"). A type of jewel worn in Spain, including the badges of the Spanish religious confraternities worn by members throughout the 17th century, such as the Order of Santiago de Compostela. One jewelled example is in the form of a gold openwork monogram 'M R', for the Virgin Mary, crowned above the monogram and set with gemstones.
From: An Illustrated Dictionary of Jewelry, autor: Harold Newman, publishers: Thames and Hudson