BOSTON — A sapphire and diamond ring by Cartier, circa 1950s, was the prevailing lot at Skinner’s September 17 jewelry auction, making quick work of its $300/500,000 estimate to settle at $873,000, including buyer’s premium. The twin stone Kashmir sapphire ring by Cartier had been owned by one family since the 1950s. The sapphires were a classic example of the cornflower-blue stones from the famed Kashmir mines, before they were depleted in the 1880s. Set with two Kashmir square-cut sapphires measuring approximately 9.21 by 8.64 by 6.55 and 9.27 by 8.75 by 6.05 mm, its platinum and diamond mount was set with tapered baguette-cut diamonds, its size was 5¾, numbered, signed. The lot was accompanied by an estimate for insurance from Cartier Inc, New York, dated January 17, 1955; and 2019 documentation stating that the sapphires are Kashmir with no gemological evidence of heat. According to the Cartier letter, the sapphires weigh 5.34 and 4.91 carats and total diamond weight is 1.26 carats. Colored stones led the way in the $2.5 million auction. Watch for a complete report.