RAPAPORT... Sotheby's garnered $18.1 million from its most recent Hong Kong auction, with a jadeite bead and diamond necklace selling for $2.3 million.The piece by designer Jacob & Co. was the star performer at the July 19 Important Jewels sale, Sotheby's said Wednesday. The auction house did not disclose the jewel's presale estimate. Another top seller was an emerald and diamond parure by Chopard. The set - which comprised a bib necklace, a bracelet, and a pair of earrings - sold for $1.4 million, within its estimate.Other notable items included a Tiffany & Co. necklace with a pear-shaped, 15-carat, D-color, internally flawless diamond pendant. Sold without a reserve price, the piece went for $1.3 million, just above its lower estimate. Meanwhile, a ring by Graff featuring an emerald-cut, 11.02-carat, D-color, internally flawless diamond flanked by tapered baguette-cut diamonds brought in $963,068, within its expected range. Two of the top 10 pieces smashed their estimates. The first, a ring bearing an emerald-cut, 20.09-carat, I-color, SI1-clarity diamond, fetched $609,943, above its $382,171 high price. The other was a pair of earrings, both featuring one diamond suspended from another. The upper stones on each piece are emerald-cut, J-color, VS1-clarity diamonds weighing 5.27 and 5.22 carats. Beneath them are pear-shaped, I- and J-color, VS2-clarity diamonds weighing 9.26 and 9.19 carats. The pair sold for $513,636, against a high estimate of $191,096. Image: The jadeite and diamond necklace. (Sotheby's)