This wonderful plique a jour flower pin is 18kt yellow gold and has a diamond trembler center. Plique a jour, is a transparent tinted glass process and in this plique a jour flower pin, the petals are mechanical. They open and close. In the center of the pin there are sixteen gold stems, each holding a diamond that shakes or trembles, hence the name "trembler pin". This pin is unusual and a one of a kind piece of jewelry. The style of these pins are very unique and well made trembler jewelery is not easy to find, especially in Plique A Jour. Beautiful! Total diamond weight is 1.60 carats.