Sévigné (French). A type of brooch in the form of a bow-knot, made of gold or silver in an openwork pattern and set with many small diamonds, sometimes having a suspended diamond or pearls. It was worn as a bodice ornament from the mid-17th century until the late 18th century. In early examples the bow-knot was simple, formal and flat, but later it became more naturalistic and three-dimensional, with unequal loops and dangling ends. It was named after the Marquise de Sévigné (1626-96), a member of the Court of Louis XIV who is famed for her letters to her daughter.
From: An Illustrated Dictionary of Jewelry, autor: Harold Newman, publishers: Thames and Hudson