Geneva's big jewelry week is under way. We report results, not estimates, so those sales go into next Tuesday's edition. This week we did something slower. We went back over every Gemfields rough auction since 2023, checked each figure against Gemfields' own announcement, and put them in one table. Two lines in it are worth your five minutes.

Key Takeaways

→ Geneva week opens. Christie's held its Magnificent Jewels sale in Geneva on November 10, with Sotheby's following on November 11 and 13. Results were not public when we wrote this. They go into the November 17 edition.

→ GIA's inclusion collection, the details. The 2,665 specimens curated over 60 years by GIA microscopist John Koivula will be cataloged in a custom database and used for GIA's education, research, and identification and origin services. Select pieces debut at the 2027 Tucson shows, and a book of photomicrographs is in preparation (National Jeweler, November 9).

→ A carved Paraíba takes Spectrum's top prize. AGTA's 2026 Spectrum Best of Show went to "Can't Look Away", a pendant by Lezlie Slavens of Luxe Fine Jewelry built around a 101.34-carat Paraíba tourmaline carved as Medusa. Cutting Edge Best of Show went to Allen Kleiman for a suite of 11 rainbow moonstone cabochons, 90.12 carats in total (National Jeweler, October 30).

The index tracks the 8 reference stones every week. Each row holds until a new dated transaction moves it. No row moves this week.

Auction results and producer averages. Tsavorite and tanzanite are trade benchmarks. Not retail. Sources: Christie's, Sotheby's, Gemfields, Bonhams, GemGuide, Pala International.

Notable this week: no new dated transaction in our eight categories. The ruby row keeps its "policy watch" flag while Mozambique's 20 percent rule is unclear. Geneva's results could move the sapphire and ruby rows next week.

Why Gemfields. Gemfields sells rough ruby from Montepuez in Mozambique and rough emerald from Kagem in Zambia, each 75% owned by Gemfields, at auctions it reports in public company announcements. It is one of the few colored-stone price series you can check line by line.

Ruby, mixed-quality auctions, Montepuez.

What it shows. The average swings with the size and the mix of each sale. The two smallest sales, June 2025 and October 2026, carry the two highest averages. National Jeweler reported that the October auction was smaller than in previous years and comprised predominantly higher-quality rubies. Gemfields' own announcement adds that selected grades and categories are now offered separately, in its Trade Select format. Trade Select's first sale, in June 2026, averaged $66.30 per carat.

Emerald, commercial-quality auctions, Kagem.

What it shows. This is the steadier line. Each of the last four sales averaged more than the one before, and the latest is about 2.2 times March 2024 (our arithmetic). Carat volumes stayed in the same range, between 2.4 and 3.9 million. The announcements give no reason for the rise, and we will not supply one.

Why it matters to you. A Gemfields average is a price for a mix of rough, sold by lot to the trade. It is not the price of a cut stone and not the price of your stone. Read it next to the carats sold and the sale category, and compare like with like.

Want the full table? All Gemfields ruby and emerald results are kept up to date on our Gemfields auction results page. For the spreadsheet and the PDF, with every row linked to Gemfields' announcement, reply to this email with the word TABLE and we will send it to you.

1. Size moves the average. In ruby, the smaller sales carried the higher averages. Check the carats sold before you read the price per carat.

2. One line is steadier than the others. Commercial-quality emerald rose at four sales in a row. Four prints are a pattern worth watching, not a forecast.

3. Categories are not interchangeable. Mixed-quality, Trade Select, mini-auctions, higher-quality and commercial-quality are different mixes of material. Putting them on one chart tells you very little.

→ Christie's Geneva, November 10. Lot 562, a ring with a 23.72-carat Kashmir sapphire, SSEF and Gübelin reports, no indication of heating, estimated at CHF 1.25 to 2 million. Lot 609, a Van Cleef & Arpels brooch with a 43.94-carat unheated Sri Lankan sapphire (Gübelin), CHF 300,000 to 500,000 (Christie's).

→ Sotheby's Geneva, November 11. The 197.80-carat unheated Ceylon "Romanov Sapphire", estimated at CHF 850,000 to 1.7 million (National Jeweler), and a 5.027-carat "pigeon blood" ruby ring at CHF 850,000 to 1.3 million (JCK).

→ Sotheby's Geneva Fine Jewelry, November 13. A 25.87-carat Ceylon sapphire ring with a high estimate of CHF 170,000 (Rapaport).

→ Christie's Hong Kong, November 24. The 21.05-carat Kashmir sapphire Cartier ring, estimated at up to $6.4 million (Rapaport).

→ Heritage Auctions, Dallas, December 7. A ring centering an 8.15-carat Kashmir sapphire leads the Holiday Fine Jewelry sale, upper estimate $500,000. Two more Kashmir sapphire rings, 7.33 and 3 carats, are estimated at $200,000 to $300,000 each (Rapaport, November 9).

→ Gemfields' December Trade Select ruby auction. The next ruby auction Gemfields has announced.

We report results, not estimates. Geneva goes into the November 17 edition.

Next time you see a producer's price per carat, look for two other numbers first: how many carats were sold, and what category of material was in the sale. If either is missing, the average tells you less than it seems.

One question for you. Which price series should we rebuild next, line by line, the way we did Gemfields? Hit reply and tell us. We read every answer.

— Carat Brief

Carat Brief is editorial. Nothing here is investment, legal, or tax advice. Gemstones are illiquid and require certified verification before purchase. Work with credentialed labs: GIA, AGL, SSEF, Gübelin, Lotus Gemology.

Sources: Gemfields auction announcements (RNS) for every Montepuez and Kagem sale listed, 2023 to 2026, including the Trade Select ruby auction of June 2026 and the October 2026 mixed-quality ruby auction; National Jeweler (Gemfields' mixed-quality ruby auction earns $52M, October 2026; GIA acquires thousands of gem specimens with "extraordinary" inclusions, November 9, 2026; Illuminating carved Paraíba pendant, suite of moonstones wow at Spectrum Awards, October 30, 2026; 197-carat Romanov sapphire heads to Sotheby's Geneva, November 2, 2026); Christie's (Magnificent Jewels Geneva preview and lot 562 page); JCK (Sotheby's Geneva sale, October 28, 2026); Rapaport (Christie's predicts $6M payday for Cartier sapphire ring, October 20, 2026; Sapphires to sparkle at Heritage auction, November 9, 2026). Derived figures are marked as our arithmetic.