A silver (800 thousandths) BRACKET centered on a gold (750) and silver (800 thousandths) marquise ring plate, with the base of the ring body already showing the rounded shape of the band. The plate is decorated with a monogram "MA" punctuated with small crowned roses set on a blue enameled guilloché background surrounded by old-cut diamonds in flap setting. Probably 18th century. This silver brooch is adorned with old-cut diamonds, a work from the 19th century, thus later than the 18th-century ring. (Transformation, numerous soldering operations). Gross weight: 22.10 g. - Dim: 4 x 3.9 cm. The "MA" monogram is indeed associated with Marie Antoinette, and can be found in the decor of the Petit Trianon at the Château de Versailles, but the monogram became extremely popular in the 19th century, during the Restoration and the Second Empire, so the presence of the monogram does not constitute proof of belonging to the queen. For this jewel to be attributed to Marie Antoinette, it would have to have..: - a documented family provenance. - a mention in a historical inventory. - archives or old certificates. Conclusion: At this stage, the MA monogram is not sufficient proof; only a documented provenance and specialized expertise could confirm a possible relationship with the Queen.