(IDEX Online) - A dazzling 19th century brooch, once owned by British royalty and featuring around 200 carats of old mine-cut diamonds, is to be sold in the US, priced at $2.65m.Antique jeweler M.S. Rau, based in New Orleans, describes the ribbon node brooch as "monumental".It says it is "both a captivating treasure and a piece of history". Henry Pelham-Clinton, the 5th Duke of Newcastle, commissioned the piece for the brooch for his wife, Lady Susan Hamilton. She first wore it to Queen Victoria's wedding in 1840.The brooch - with an array of large pear-cut and cushion-cut diamonds - was reputedly crafted by famed French jeweler Maison Babst, the Crown Jewelers to the French court for decades.The design is thought to have been inspired by Empress Eugenie's bowknot, an iconic jewel that is now in the Louvre.Pic courtesy M.S.Rau