Emerald Up. Ruby Held Back.

Five days ago, Gemfields closed its higher-quality emerald auction in Bangkok. Three months ago, it closed its mixed-quality ruby auction in the same city. Same operator. Same selling format. Same buyer pool. Two completely different stories.

The emerald sale cleared $26.8 million at an average of $146.08 per carat. Thirty-six of thirty-seven lots sold. Ninety-nine percent of carats found a buyer. Demand was firm enough that Adrian Banks, Gemfields' MD of Product & Sales, called pricing for top-tier emeralds "particularly strong."

The ruby sale, in February, cleared $53 million at $279 per carat — a respectable result, with strong demand for fine-quality and fluorescent rubies, but softer bidding in other segments. Gemfields has now formally scaled back its June 2026 ruby auction and reserved the right to flex the size, frequency and timing of further 2026 ruby auctions. The reasons given in writing: lower-than-expected Montepuez production, concerns about liquidity in the ruby market, weak Chinese demand, and pressure from illegal artisanal mining inside the concession area.

The classic "Big Three" framing : sapphire, ruby, emerald as a single asset class — doesn't survive contact with this data.

→ $26.8M / $146.08 per carat — Gemfields higher-quality emerald auction, Bangkok, 4–21 May 2026. 36 of 37 lots sold. 99% of the 185,135 carats on offer cleared. Average price down from $160.78/ct at the September 2025 sale, partly attributed to a ~10% depreciation of the Indian rupee vs the dollar over the period (LSE, Mining Weekly).

→ June ruby auction scaled back — Gemfields cites lower-than-expected ruby production at Montepuez, liquidity concerns, subdued Chinese demand. A smaller-than-usual June auction will offer selected grades. The company is keeping flexibility on size, frequency and timing for the rest of 2026 (Sharecast).

→ EU sanctions on Myanmar renewed — Regulation 401/2013 renewed through 30 April 2027 on 27 April 2026. EU/US/UK markets remain closed to rubies traceable to military-controlled production channels (Council of the EU).

The Carat Brief Index tracks the 8 reference stones every Tuesday. Each stone is anchored to its most recent verifiable public transaction (auction realized, or producer auction average price), or to published trade benchmarks where no recent public sale exists. Auction prices are realized, not retail.

Sources: Gemfields, Christie's, Sotheby's, Bonhams, Diamond World, Mining Weekly, GemGuide, Pala International.

Notable this week: The emerald price retreated from $160.78/ct (Sep 2025) to $146.08/ct in May 2026, on 99% sell-through. Gemfields and trade press attribute this primarily to a ~10% depreciation of the Indian rupee vs the USD over the period, repricing Indian dealer participation. On the ruby side, the more telling data point isn't the per-carat average — Gemfields explicitly cautions that lot composition varies and averages aren't directly comparable — but the operator's own decision to scale back the June 2026 auction. When a producer voluntarily contracts supply, the signal is stronger than the price.

Gemfields is the largest traceable producer of colored stones in the world. Two flagship operations: Kagem (emerald, Zambia, 75% owned) and Montepuez Ruby Mining / MRM (ruby, Mozambique, 75% owned). Between 2023 and mid-2025, both moved roughly in tandem. Since the second half of 2025, they have diverged sharply.

Mixed-quality ruby auction history at Montepuez:

Per-carat averages across Gemfields auctions are not directly comparable because lot composition varies by size, color and clarity (Gemfields disclaimer).

Source: Gemfields auction updates.

The February 2026 sale was deferred from December 2025 to allow the new PP2 processing plant at MRM to come online. PP2 is expected to roughly triple processing capacity once fully commissioned. So far the rampup has not delivered the production volumes Gemfields modeled. Combined with sustained illegal mining (estimated 250-400 individuals operating daily inside the MRM concession, per Gemfields communications throughout late 2025), and weakening Chinese demand for mid-grade rubies, the operator is now openly cautious about pushing more material to market.

Higher-quality emerald auction history at Kagem:

Source: Gemfields, Sharecast.

The May 2026 result is softer in nominal terms but Gemfields signals structural stability, not a downturn. The number of bidding companies fell from 65 in September to 57 in May. Banks specifically attributed the drop to: "a weaker Indian rupee" (Indian buyers are a major share of the bid pool, and a 10% currency depreciation effectively raises their cost basis by 10%). The 99% sell-through on carats argues the demand is there — just price-sensitive.

This is the central insight Carat Brief is built to deliver: colored stones do not move as a class. The investor or dealer who treats sapphire, ruby and emerald as a single category will misread every cycle.

This isn't theory. The next 12 months will show very different price action for the same operator's two main outputs — and Carat Brief readers will see it before the trade press synthesizes it.

In mid-April 2026, miners near Mogok, Myanmar, unearthed a single rough ruby weighing approximately 11,000 carats (2.2 kg) (Discovery Alert). The find is geologically extraordinary but commercially complicated: under current US, EU and UK sanctions regimes, rubies traceable to Myanmar's military-controlled production channels cannot legally enter Western markets. The stone will most likely route through China, the primary destination for sanctioned Burmese gem material since 2021. Watch whether SSEF, Gübelin and AGL issue clarifying language on origin reports for stones surfacing from Mogok in 2026.

On 27 April 2026, the Council of the EU formally renewed Regulation 401/2013 (the framework for restrictive measures against Myanmar) for another year, through 30 April 2027 (Council of the EU). The renewal preserves the asset freeze, export bans on dual-use goods, and travel restrictions on listed individuals. For the colored stone trade, the key consequence is that Burmese ruby origin papers remain a liability in EU jurisdictions for at least another twelve months. This continues to push premium per-carat prices for the legacy stock circulating in the secondary market — older Burmese rubies with pre-2021 provenance now trade at meaningful premiums to comparable Mozambique material.

CNBC reported in March 2026 that wealthy consumers are increasingly turning to jewelry — specifically colored gemstones — as an inflation hedge and store of value. Jacqueline DiSante, VP and Head of Sales at Christie's New York Jewelry, framed the thesis in plain language: "In a world where we are seeing lab-grown diamonds being made, and it kind of feels like this conveyor belt... you can't do that with a sapphire or ruby or emerald" (CNBC). When a Christie's executive goes on record at this level, the institutional repositioning is real, not aspirational.

→ Gemfields June 2026 ruby auction (Bangkok, dates TBA). Scaled-back format with "selected grades tailored to prevailing market demand." Watch the average per-carat and the bid count. If those numbers stabilize, the ruby thesis holds. If they slip further, expect Gemfields to flex auction frequency for H2 2026.

→ Sotheby's New York Magnificent Jewels — Spring sale season closing. Coloured stone lots from estate provenances tend to perform asymmetrically when sanctioned-origin rubies surface with documented pre-2021 papers.

→ Christie's London Magnificent Jewels — June sale window. Mid-range Kashmir sapphire lots (5-15 ct) will tell us whether the per-carat repricing seen at the top of the curve in recent auctions is extending down-market, or staying concentrated at the apex.

Pro launches at 500 subscribers. Founding rate: $99/year locked for life.

Reply "PRO" to lock the founding rate.

Forward this to one person who still thinks "colored stones" is one market.

— Carat Brief

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