Auction monitor

Every disclosed 2026 sale

Gemfields is the only large producer that publishes per-auction results. Each table compares only sales in the same category.

2026 calendar

Five auctions, four formats

Sale	Format	Venue	Revenue	Lots sold	Carats sold / offered	US$/ct	Source
9–20 Feb	Mixed-quality ruby	Bangkok / online	$53.0m	121/135	189,620 / 214,509	279.39	RNS 23 Feb
4–21 May	Higher-quality emerald	Bangkok / online	$26.8m	36/37	183,385 / 185,135	146.08	RNS 22 May
22–29 Jun	Trade Select ruby (+ sapphire)	—	$23.1m	82/89	348,409 / 374,008	66.30	RNS 30 Jun
24 Aug–10 Sep	Commercial-quality emerald	Jaipur / online	$29.6m	44/44	3,047,650 / 3,047,650	9.72	RNS 11 Sep
5–16 Oct	Mixed-quality ruby	Bangkok	$52.0m	90/99	92,153 / n.d.	564.54	Report 19 Oct
Total disclosed, 2026 to date Derived			$184.5m

n.d. = not disclosed in the sources reviewed (October offered weight was described only as "slightly over 20 kg"). Gemfields has said the next Trade Select ruby auction is planned for December 2026.

Series · Montepuez, Mozambique

Mixed-quality ruby

Auction	Revenue	Lots sold	Carats sold / offered	% by weight	US$/ct
Dec 2023	$69.5m	97/97	239,591 / 239,591	100%	290.02
Jun 2024	$68.7m	94/97	216,600 / 217,044	99.8%	316.95
Dec 2024	$46.2m	97/102	143,613 / 167,865	86%	321.94
Jun 2025	$31.7m	78/90	68,705 / 99,830	69%	461.48
Feb 2026	$53.0m	121/135	189,620 / 214,509	88%	279.39
Oct 2026	$52.0m	90/99	92,153 / n.d.	n.d.	564.54

Smaller formats are excluded from this series: an April 2025 mini-auction ($7.2m), a Sep–Oct 2025 mini-auction ($11.0m; 26 of 33 lots) and the June 2026 Trade Select ($23.1m). The usual Nov–Dec 2025 auction was deferred to February 2026.

Series · Kagem, Zambia

Higher-quality emerald

Auction	Revenue	Lots sold	Carats sold / offered	US$/ct
Jun 2023	$43.7m	35/35	264,132 / 264,132	165.55
May 2024	$35.0m	43/46	208,990 / 240,000	167.51
Nov 2024	$16.1m	30/43	141,084 / 200,460	113.96
Sep 2025	$32.0m	38/38	199,103 / 199,103	160.78
May 2026	$26.8m	36/37	183,385 / 185,135	146.08

Excluded: a February 2025 second-round sale of unsold November 2024 lots ($4.8m; 10 of 13 lots; $105.49/ct).

Series · Kagem, Zambia

Commercial-quality emerald

Auction	Revenue	Lots sold	Carats sold / offered	% by weight	Bidders	US$/ct
Mar 2024	$17.1m	40/43	3,854,950 / 4,171,375	92%	50	4.45
Aug–Sep 2024	$10.8m	28/46	2,423,550 / 3,978,450	61%	39	4.47
Apr 2025	$16.4m	32/36	2,388,190 / 3,029,690	79%	50	6.87
Nov–Dec 2025	$25.4m	45/46	3,406,830 / 3,656,830	93%	55	7.46
Aug–Sep 2026	$29.6m	44/44	3,047,650 / 3,047,650	100%	63	9.72

Stone intelligence

One category. Three different markets.

Price per carat means little without species, origin, colour, size, treatment and laboratory report. Each stone below is described by its own evidence.

◆ Ruby

Observable supply: Montepuez (Mozambique) is the source of every Gemfields ruby sale. Gemfields sold $128.1m of ruby across three 2026 auctions.

What changed in 2026: premium grades roughly halved, a Trade Select format was added, and the October sale was smaller and weighted to higher qualities. Its $564.54/ct is the highest in the published mixed-quality series.

Demand notes: in February Gemfields reported strong pricing for fine rubies but muted bidding for some other qualities, which it partly attributed to extra supply from illegal mining in the area and weaker Chinese demand.

Prestige origin: Myanmar (Mogok). Sanctions and traceability rules require origin diligence. Context

◆ Sapphire

Observable supply: Gemfields first offered sapphire categories, from Montepuez corundum, at its June 2026 Trade Select sale. The headline results combined them with ruby.

Key origins: Sri Lanka and Madagascar are major sources and trading centres. Kashmir material is historic and very scarce. Context

Pricing: no producer publishes a regular sapphire auction series, so this site shows no sapphire price figure.

◆ Emerald

Observable supply: Kagem (Zambia) runs two series, higher-quality and commercial-quality. 2026 revenue so far is $56.4m.

What changed in 2026: the commercial sale cleared all 3.05m carats at $9.72/ct, the highest of the last five commercial sales. The higher-quality sale made $146.08/ct, below September 2025's $160.78. Gemfields cited buyer caution over geopolitics and a rupee down about 10% against the dollar.

Prestige origin: Colombia. Clarity enhancement (type and degree of oil or resin) is central to valuation. Context

◇ Beyond the big three

Spinel, Paraíba-type tourmaline, tanzanite, alexandrite, jadeite and opal each need their own pricing framework. They should not be combined into one per-carat series. These profiles are planned but not yet published.

Origin & supply

Follow the geology, then the market.

Most coloured gemstones come from artisanal and private producers that publish nothing. The two large operations that do publish are covered first.

Montepuez Ruby Mining · Mozambique · 75% Gemfields

Lower grades, fewer auctions

0.06 → 0.03 ct/t

Overall premium ruby grade: FY2025 vs. five months to 31 May 2026. Reported

0.02 ct/t

Premium ruby grade from the Mugloto domain, five months to 31 May 2026. Reported

$28.3m

VAT refunds owed to MRM at 30 June 2026. Gemfields described the impact on cash flow as materially negative. Reported

Schedule cut

In May 2026 Gemfields cut back its ruby auctions, citing lower production, weak liquidity in the ruby market and softer Chinese demand. It has kept flexibility over the size and timing of later sales. Reported

MRM's second processing plant reached its 400 t/h design capacity by February 2026, but Gemfields said further adjustments were needed for sustained operation at that rate.

Kagem · Zambia · 75% Gemfields

Emerald operations recovering

Kagem suspended mining in January 2025 and reopened two mining points in May 2025, after the commercial-quality market began to recover. Commercial-quality prices have risen at each of the last five sales, from $4.45/ct (March 2024) to $9.72/ct (September 2026).

Other origins

Where disclosure is thin

Myanmar

Historic source of prestige ruby and sapphire. Sanctions, responsible sourcing and traceability need diligence. Context

Colombia

The benchmark origin for fine emerald. Origin reports carry weight in high-end trades. Context

Sri Lanka

A major sapphire source with a long-established trading and cutting industry. Context

Madagascar

Supplies many coloured stones, including sapphire, mostly from artisanal mining. Context

Pricing & treatment

Never reduce a gemstone to one number.

Compare like with like: species and variety → colour → size → origin opinion → treatment → clarity and cut → laboratory → sales channel.

Natural vs treated

Natural colour does not mean untreated. Record heating, fracture filling and oil or resin enhancement separately from laboratory commentary.

Origin opinion

A laboratory origin finding is a scientific opinion on the available evidence. It is not proof of chain of custody.

Auction averages

Average US$/ct follows the mix offered. In 2026, Gemfields' ruby averages ranged from $66.30 (Trade Select) to $564.54 (mixed-quality) within four months, because the goods differed, not the market.

Building a real index

A matched-stone price series would need fixed size bands, grades, origin opinion, treatment status, channel and period. None is published for coloured stones today.

Trade data

Separate coloured gems from all gemstones.

USGS reports one gemstone category that includes diamonds. It is shown here for scale, not as a measure of coloured-gem demand.

USGS Mineral Commodity Summaries 2026 · United States · US$ millions

U.S. gemstone trade, all types including diamond

Item	2021	2022	2023	2024	2025e
Imports for consumption	24,600	28,700	24,200	19,600	11,000
Exports (excl. re-exports)	992	1,890	3,610	2,110	1,700
Apparent consumption	23,700	26,900	21,300	17,600	9,300
Natural production	9.48	9.95	10.0	9.25	9.4

USGS puts 2025 imports at about $11bn, down 44% from $19.6bn in 2024. Its commentary for the chapter focuses on the natural diamond downturn and gives no coloured-stone breakdown.

U.S. tariff treatment (USGS)

Cut rubies, sapphires and emeralds enter duty-free. Uncut and worked "other non-diamond gemstones" carry 10.5% ad valorem. Synthetic gemstones carry 3% (unworked) or 6.4% (worked).

For coloured-only trade analysis, a production build would use HS-level customs data (HS 7103), adjust for re-exports, and split rough from cut and natural from synthetic.

Market signals

What the 2026 disclosures say

Each signal is a producer's own reported observation, dated, with our reading kept separate.

◆

Oct 2026 · Fine ruby carries the market

$52.0m from a smaller sale of mostly higher-quality rubies, with Gemfields citing particularly strong prices for larger fine stones. Our reading: this shows depth at the top end. It is not evidence that ruby prices rose generally.

Gemfields via Engineering News, JCK · 19–21 Oct 2026

⬡

Sep 2026 · Commercial emerald clears in full

The first commercial sale in nine months sold every lot and every carat, to the largest bidder field (63) of the last five sales.

Gemfields RNS · 11 Sep 2026

◆

Jun 2026 · New format, broader mix

Trade Select sits between mixed-quality auctions and the 2025 mini-auctions. It offered a wider range of ruby qualities and, for the first time, sapphire. Gemfields said conditions remain challenging in some segments.

Gemfields RNS · 30 Jun 2026

⬡

May 2026 · Caution at the top of emerald

$26.8m at $146.08/ct. Competition for the finest stones was strong, but buyers were cautious overall. A rupee about 10% weaker against the dollar since September 2025 added pressure on Indian buyers.

Gemfields RNS · 22 May 2026

◆

Feb 2026 · Two-tier ruby demand

Fine-quality rubies sold strongly. Bidding for some other qualities was muted, which Gemfields partly attributed to extra supply from illegal mining in the area and weaker Chinese demand.

Gemfields RNS · 23 Feb 2026

◫

Structural · Why no index exists

Private production, inconsistent grading and few repeat sales make a coloured-gemstone price index hard to build. This site publishes observed transactions and does not construct one.

Methodology

Sources & method

Every number needs a definition.

This is a static research snapshot with a cut-off of 29 October 2026. It does not draw on a live pricing or news feed.

Reported

A figure published by the issuer or a public authority, shown for its stated period and scope.

Derived

Arithmetic on reported figures, such as totals or ratios. The inputs are always shown.

Context

Established industry knowledge with no single dated statistic behind it. Never used for numbers.

Not comparable

Averages from different auction formats or quality mixes are never charted together.

Primary sources

Secondary reporting

Known gaps

The October 2026 ruby figures come from press reports of the Gemfields announcement. The issuer RNS link should be added once it is archived. Carats offered at that sale were not disclosed in the sources reviewed.