Vintage Solitaire Marquise Amethyst Ring in 14k.  This stunning Art Deco cocktail ring features a 5.31 carat marquise cut amethyst set in 14 karat white gold. The center stone is very thick for a marquise cut and is beautifully bordered by deep angular engravings just outside of the bezel. The filigree work below the amethyst is dazzling to stare into, with the polished white gold bright and shining.