A PAIR OF ONYX AND DIAMOND PENDENT EARRINGS, BY MARGHERITA BURGENER Each elongated onyx drop, suspending from four brilliant-cut diamonds within collet-setting, to a circular onyx plaque and brilliant-cut diamond surmount, mounted in 18K gold, signed Margherita Burgener, with maker's marks, Italian assay marks, with maker's case, length 7.2cm Each elongated onyx drop, suspended from square-cut ruby and diamond-set connectors, to a rectangular-cut aquamarine surmount, mounted in 18K gold, maker's marks MB, Italian assay marks, with maker's case, length 7cm