Gemstone Market Update: A Kashmir Sapphire Carries a $1.2 Million Estimate

September 22, 2026

A 9.86-carat sapphire will provide a striking test of collector interest at Phillips’s September 29 Hong Kong jewelry auction. Set in a mount stamped Bulgari, the stone is accompanied by Gübelin and SSEF reports identifying Kashmir origin with no indications of heating. Phillips estimates the ring at HK$7.5 million to HK$9.5 million—approximately US$962,000 to US$1.22 million. The sale is still ahead: these figures are estimates for a particular finished jewel, not a completed transaction or a price guide for other sapphires. View the auction lot.

Another highlight brings a different kind of rarity: a 7.45-carat Brazilian alexandrite ring estimated at US$295,000 to US$410,000. GIA explains that most cut alexandrites weigh less than one carat, which gives useful perspective on its size. The attraction also lies in the stone’s change of color under different lighting. The trade term for this edition is “color change”: in fine alexandrite, green to bluish green in daylight gives way to red to purplish red under incandescent light. Size alone does not establish quality; the strength and appearance of that change matter. View the alexandrite lot and GIA’s explanation.

Laboratory paperwork deserves careful attention alongside those impressive numbers. In a June 15 trade alert, SSEF described emeralds that had been cleaned, tested, then filled again after a report was issued. A genuine report could consequently describe an earlier condition of the stone. That warning remains useful background for current transactions: report verification and confirmation that a gemstone has not subsequently been altered address different questions. Read the laboratory’s alert.

Five stones on this edition’s market watch list

This selection follows notable lots in the forthcoming Phillips sale. It is an editorial watch list, rather than a measured worldwide ranking of demand.

• Sapphire: The Kashmir ring leads the auction’s estimates, putting documented origin and treatment status in focus.
• Emerald: A 15.50-carat Colombian emerald ring carries an upper estimate of HK$4 million.
• Alexandrite: The 7.45-carat Brazilian example combines unusual size with the variety’s color-change appeal.
• Jadeite: A jadeite-and-diamond ring is estimated as high as HK$2.8 million, showing the category’s place among the sale’s major lots.
• Ruby: A 6.06-carat Mozambican ruby ring also has an upper estimate of HK$2.8 million.

Browse the Phillips auction. These estimates do not establish that any gemstone category has risen in value.

Natural gemstones offer individual combinations of color, formation and history. For help sourcing natural colored stones through the secondary market, with attention to available origin and treatment documentation, enter the Pryce House Stone Room.