Colored Gemstones
Supply lines drawn in emerald, ruby and sapphire
The most opaque corner of the trade — and the most alive. The gemstone desk tracks auction results from Zambian emerald and Mozambican ruby tenders, the cutting rooms of Bangkok and Jaipur, treatment disclosure fights, and the collector demand pushing top stones past diamonds.
Latest
Gemfields ruby auction raises $52.0m at $564.54 a caratMontepuez Ruby Mining sold 92,153 of the 102,099 carats offered, about half February's weight. Gemfields says its Trade Select strategy now sells some grades separately; the next such sale is planned for December.- 81.17-carat Paraiba leads Bonhams Paris on 29 OctoberThe neon-blue cushion-cut tourmaline carries a €60,000 to €80,000 estimate. Two unheated sapphires over 10 carats, signed Cartier and Chaumet, follow at €40,000 to €60,000 and €45,000 to €65,000.
- Le Vian prices 17 antique-cushion styles from $1,499.99The cut arrives at Kay Jewelers in mid-October across eight natural gemstones, from nude quartz to rose morganite. The in-store range tops out at $4,999.99, with further designs online.
- HKD 1.8 million tops Poly Auction's Hong Kong jewellery saleA Van Cleef and Arpels sapphire and diamond necklace led the 6 October High Jewelry and Important Watches sale. Burmese ruby and cabochon sapphire earrings cleared their high estimate by more than twice.
- Mejuri swaps lab-grown diamonds for sapphires in four stylesThe Toronto brand put Montana stones into its Salmon Gold line, pricing two rings, a charm and earrings from $498 to $896. It invested $1.5 million in the Regeneration project in 2023.
- Gemfields revenue reaches $106.0m as net debt falls to $44.2mThe reviewed accounts for the six months to 30 June carry figures September's trading statement did not. EBITDA was $40.7m against a $4.9m loss a year earlier, and net asset value fell to $248.3m.
- Gemfields restates 2025's writedown to $65.0m from $35.0mGemfields expects a $73.5m net loss for the six months to 30 June, after a $125.2m impairment at Montepuez. That compares with a $20.5m loss a year earlier, and interim results follow on 30 September.
- AGTA takes 12.5% gemstone tariff to Bangkok trade talksThai finished jewellery entering the United States carries combined duties of 17.5% to 19.5%, the association says. It met Thailand's vice minister for commerce and passed the discussion to the US Trade Representative.
- Thailand's gold exports fall 59.22% in July to US$411.04mGem and jewellery exports excluding gold slipped 6.36% to US$737.93m, the first monthly fall after four straight gains. Seven-month exports excluding gold still run 9.87% ahead at US$8,981.12m.
- SCS retires SCS-007, the gemstone standard no miner adoptedThe scheme covered natural and laboratory-grown diamonds, emeralds, rubies and sapphires, and ended on 1 September. Companies already certified may use their certificates until expiry, but SCS will no longer audit or maintain the standard.
- Gemfields sells all 44 emerald lots for $29.6 millionThe commercial-quality sale cleared at $9.72 a carat, up 30.3% on the November-December auction's $7.46. Bidding companies numbered 63, the widest field of the five most recent commercial sales.
- Pigeon blood, issued in Jaipur: GSI brings the trade names homeGSI now issues Pigeon Blood, Royal Blue and Padparadscha reports from Jaipur, Mumbai, New York and Bangkok. Untreated stones only. Jaipur cuts the world's finest rubies and could not name them at home.
- A fourth source for Paraíba: GIA and Gübelin both put Ethiopia on the mapTwo laboratories said on 27 August that Ethiopian copper-bearing tourmaline meets the Paraíba definition. Gübelin first saw the material in May, GIA in June, and GIA studied a parcel of more than 100 rough and faceted stones.
What’s moving now
Market · Global
The big three outrun diamonds again
Untreated Burmese rubies, Kashmir-quality sapphire and vivid Colombian emerald keep setting per-carat records. Scarcity is structural: the great mines are old and the new finds are small.
Certification · Lucerne
Origin is the price
A ruby's passport matters as much as its color. Lab reports naming Mogok or Kashmir multiply value — which makes origin science, and origin fraud, the desk's permanent beat.
Supply · Lusaka
Tender economics tighten midstream
Producer tenders in Zambia and Mozambique now set benchmark rough prices with auction transparency — squeezing the traditional dealer margin and professionalizing a famously handshake market.
The working vocabulary
The trade’s terms, plainly told. More in the Field Guide.
- The Big Three Term
- Emerald, ruby, sapphire — the trio that anchors colored-stone value. Everything else, however beautiful, trades as 'semi-precious' economics with rare exceptions like paraíba and spinel.
- Treatment disclosure Practice
- Most gems are heated, oiled or filled to improve appearance; the sin isn't treatment, it's silence. 'No indications of heating' on a lab report can multiply a stone's price tenfold.
- Origin determination Science
- Labs read a stone's chemistry and inclusions like a birth certificate — Mogok ruby, Panjshir emerald, Ceylon sapphire. It's expert judgment, not barcode certainty, and labs occasionally disagree.
- Pigeon's blood Grade
- The trade's most contested color term: the pure vivid red, historically Burmese, that marks the summit of the ruby market. Whose lab gets to say it is a running commercial war.
On the record
What this desk filed in the last eight weeks, dated and sourced.
This week, August 20 to September 23
Gemfields' 'smaller than previous years', against its own table
Corrected 21 October 2026: gemfields-ruby-auction-raises-fifty-two-million.html (No. 092, 20 October 2026) carried, unqualified, Gemfields' line that the October sale was smaller than previous years'. Its own table shows June 2025 offered fewer carats, 99,830 against 102,099. The sentence now says so. What was right as published: every figure.
Source: Carat Capital, a-gemfields-ruby-auction-raises-fifty-two-million.html; Carat Capital standards audit, 2026-10-20; RNS re-read (80,875 bytes)
This week, August 20 to September 23
Gemfields restated its 2025 writedown to $65.0m from $35.0m
Gemfields' trading statement of 25 September 2026 restates the impairment booked for FY2025 to $65.0m from $35.0m, an adjustment of $30.0m for which the announcement gives no cause, deferring the explanation to its interim statements. For the six months to 30 June 2026 the company expects a net loss after tax of $73.5m against $20.5m a year earlier, driven by a non-cash impairment of $125.2m at the Montepuez ruby mine. Auction revenue rose to $102.8m from $60.0m. Headline earnings per share, which strips the impairment out, turned positive at USDc 0.6 against a 1.5c headline loss. The restatement was not carried in the secondary trade coverage of the same statement. Corrected 30 September 2026: the article's depth section said the +0.6-cent headline figure meant the half broke into profit on a per-share basis for the first time in a year. None of the three sources cited gives Gemfields' headline earnings per share for the second half of 2025, so the superlative was uncited and has been removed; the sentence now gives only the 0.6-cent headline figure against a 1.5-cent headline loss a year earlier. Every figure named here was correct as published and is unchanged.
Source: Gemfields Group Limited, Trading Statement for six months ended 30 June 2026, RNS and SENS, 25 September 2026
This week, August 20 to September 23
Thailand's gold exports fall 59.22% in July to US$411.04m
Gem and jewellery exports excluding gold slipped 6.36% to US$737.93m. Seven-month exports excluding gold run 9.87% ahead at US$8,981.12m.
Source: GIT July 2026 release via Manager Online, 10 September 2026; GIT infocenter, 7 September 2026
This week, August 20 to September 23
SCS retires SCS-007, the gemstone standard no miner adopted
SCS Standards retired SCS-007, its sustainability certification for natural and laboratory-grown diamonds, emeralds, rubies and sapphires, effective 1 September 2026. Certificates already issued run to their expiry date; no audits continue.
Source: SCS Standards and SCS Global Services retirement notices, read 19 September 2026; JCK, 18 September 2026
This week, August 20 to September 23
Gemfields sells all 44 emerald lots for $29.6 million
Gemfields' commercial-quality emerald auction took $29.6 million, with all 44 lots placed at an average $9.72 a carat. The goods came from Kagem in Zambia.
Source: Gemfields Group Limited, Auction Results: Commercial-Quality Emeralds, 11 September 2026