Platinum, Black Opal and Diamond Pendant-Necklace, Marcus & Co., Circa 1910-1915. photo Sotheby's The pendant set with an ovoid black opal measuring approximately 36.0 by 24.5 by 5.1 mm., within a garland-style mounted set with old European-cut and single-cut...

Platinum, Gold, Citrine, Jade and Diamond Pendant-Necklace. photo Sotheby's The pendant set with an octagonal-shaped citrine weighing approximately 170.00 carats, surmounted by an openwork plaque set with old European-cut diamonds weighing approximately...