Program aims to educate young consumers about mined stones’ positive qualities.
May auction will feature 25 pieces by the designer.
Late Austrian billionaire’s jewelry assortment set to be most valuable in auction history.
Diamond necklace leads auction with price of $5.9 million.
Pear-cut, 31.62-carat stone set in pendant a top item at New York Magnificent Jewels.
Sale price hits just above lower end of estimate.
Square emerald-cut Graff ring will be one of the lead items at November 8 Geneva Magnificent Jewels auction.
18.18-carat gem is largest pear-shaped stone to be offered at auction.