Program aims to educate young consumers about mined stones’ positive qualities.
Many top lots fall short of low estimates or fail to find buyers entirely.
Ring brings in $25.3 million at Sotheby’s Hong Kong, just below $26 million low estimate.
Top item at October 6 Magnificent Jewels sale expected to bring in up to $5.1 million.
17.61-carat stone is largest internally flawless gem of its color ever to appear at auction.
Gems linked to Austrian Habsburg dynasty make first appearance in nearly a century.
126.76-carat stone appeared without reserve at New York Magnificent Jewels auction.
Selection includes a sapphire and diamond necklace carrying a $3.5 million upper estimate.
Eye bangle fetches nearly $1 million at Geneva Magnificent Jewels.
Mozambique-mined Estrela de Fura may set new auction record.
Signed jewels and white diamonds are some of the safer bets for collectors, insiders say.