GEMNYX market intelligence
Source-specific coloured-gemstone market intelligence: two separate Zambia emerald auction-average indexes, a Mozambique mixed-quality ruby index and format-separated Mozambique auction history. These market measures are independent of GNRC valuation.
Consumer market · D2C retail asking prices
In developmentWe are building a separate index to track advertised consumer prices for loose coloured gemstones. Initial work focuses on ruby, sapphire and emerald, with comparable stones grouped by size, treatment and cut. It will measure asking-price trends—not confirmed sales or individual valuations.
Size, treatment and cut define the comparison. Faceted stones and individual cabochons stay separate; pairs and parcels remain separate research, not individual-stone constituents.
Development uses dated retailer observations and checks comparable monthly evidence, source independence and coverage before any price trend can be released.
Rough auctions, wholesale transactions and The Mint or GNRC inventory are not constituents. This development does not change valuation, GNRC, RVB or NAV.
No D2C index level or price movement is published. No launch date is committed.
Read the evidence rulesZambia · Release 1
Two separate indexes of disclosed rough-auction averages from Gemfields’ Kagem mine. Each index equals 100 × the reported event price per carat ÷ the reported base-auction price per carat. These are composition-unadjusted auction-average measures, not constant-quality gemstone prices or investment returns.
Data courtesy of Gemfields auction results
Zambia · Higher-quality rough emerald
Latest auction-average index level
21 May 2026
Down 9.14% since previous auction
11.76% below the base auction average. Click a number or chart point to see why.
Base 1 Jun 2023 = 100 · 5 observed auctions
| Auction ended | USD / ct | Index | Since previous | Versus base |
|---|---|---|---|---|
| — | 0.00% | |||
| +1.18% | +1.18% | |||
| -31.97% | -31.16% | |||
| +41.08% | -2.88% | |||
| -9.14% | -11.76% |
Zambia · Commercial-quality rough emerald
Latest auction-average index level
10 Sept 2026
Up 30.29% since previous auction
118.43% above the base auction average. Click a number or chart point to see why.
Base 22 Mar 2024 = 100 · 5 observed auctions
| Auction ended | USD / ct | Index | Since previous | Versus base |
|---|---|---|---|---|
| — | 0.00% | |||
| +0.45% | +0.45% | |||
| +53.69% | +54.38% | |||
| +8.59% | +67.64% | |||
| +30.29% | +118.43% |
One public issuer (1 source group). Lines join observed auction events on calendar dates; no monthly estimates, interpolation or annualized return. Quality, grade and sold-lot mix can change between auctions. The two bases differ and the series are not blended.
Public aggregate disclosures: Gemfields Group Limited. GEMNYX-PE-3.0 · GEMNYX-MEI-ZAMBIA-2026-11-07-R1. The frozen input hashes and record-level audit trail are retained for external review. This release does not create an investment-return benchmark or change D2C, GEMNYX valuation, GNRC, RVB, NAV or pricing factors.
Mozambique · Public auction evidence
A separate index of regular mixed-quality rough-ruby auction averages from Gemfields’ Montepuez Ruby Mining operation. This composition-unadjusted measure compares auction averages, not the price of an unchanged ruby: quality, grade and the mix of stones sold can differ each time. It is not a constant-quality gemstone price index or an investment return.
Data courtesy of Gemfields auction results
Latest included auction-average index level
20 Feb 2026
-39.46% versus the previous included auction · +128.95% versus base.
Base 9 Jun 2018: $122.03 / ct = 100. 10 included events from one public issuer (1 source group).
| Auction ended / disclosed month | USD / ct | Index | Since previous included | Versus base |
|---|---|---|---|---|
| Base — no prior | 0.00% | |||
| -30.90% | -30.90% | |||
| -38.34% | -57.40% | |||
| +48.34% | -36.80% | |||
| +244.90% | +117.97% | |||
| +9.03% | +137.66% | |||
| +9.29% | +159.73% | |||
| +1.57% | +163.82% | |||
| +43.34% | +278.17% | |||
| -39.46% | +128.95% |
21 source-supported events. Hover over a point for its date and reported USD/ct, or click for sources and format details. Three month-only observations are labelled explicitly. This format-separated history is not a continuous price index or a sapphire-only series.
April 2021: a major unsold lot raised the realised average. October 2026: a smaller, higher-grade-heavy offering followed the Trade Select change. Neither is a like-for-like price gain. December 2021, June 2022 and December 2022 remain excluded until verified. Small commercial and by-product prices are clearer in the log view or table.
| Auction ended / disclosed month | USD / ct | Format |
|---|---|---|
| Corundum / by-product | ||
| Early higher-grade ruby | ||
| Corundum / by-product | ||
| Early higher-grade ruby | ||
| Mixed-quality ruby | ||
| Mixed-quality ruby | ||
| Mixed-quality ruby | ||
| Mixed-quality ruby | ||
| Mixed-quality ruby | ||
| Mixed-quality ruby | ||
| Commercial-quality | ||
| Mixed-quality ruby | ||
| Mixed-quality ruby | ||
| Corundum / by-product | ||
| Mixed-quality ruby | ||
| Mini ruby auction | ||
| Mixed-quality ruby | ||
| Mini ruby auction | ||
| Mixed-quality ruby | ||
| Trade Select | ||
| Mixed-quality ruby |
GEMNYX-PE-3.0 · GEMNYX-MEI-MOZAMBIQUE-2026-11-07-R1. The 21-event history starts in 2014 and keeps auction formats separate; the 10-event index starts in June 2018. December 2021, June 2022 and December 2022 are not published as unverified observations. This public evidence release does not change Zambia’s series or feed D2C, pricing factors, GEMNYX valuation, GNRC, RVB, NAV or GPI.
The design principle
An asking-price catalogue, verified wholesale transaction, rough-auction outcome and published price reference do not represent the same market event. GEMNYX keeps them distinct instead of creating a broad number that hides those differences.
The release keeps source, country, auction tier and material form visible. A future summary view, if approved, would disclose what it contains rather than presenting unrelated data as one price series.
Source-separated market context
Publicly disclosed, mine-level aggregate outcomes are retained as a distinct rough-market research series.
MRM ruby rough
$564.54/ ct
Mixed-quality (predominantly higher-quality) · ended 16 Oct 2026
Source-stated proceeds $52,000,000.0 · 90/99 lots sold
Kagem emerald rough
$9.72/ ct
Commercial-quality · ended 10 Sept 2026
Source-stated proceeds $29,600,000.0 · 44/44 lots sold
These are aggregate rough-auction outcomes, not individual-stone comparables, polished-gem prices, a published index level, or an input to GNRC, RVB, NAV or GEMNYX valuation.
Release governance
A cell needs comparable observations over time, not one catalogue capture.
Stone type, material form and other relevant characteristics remain visible instead of being blended away.
Definitions, source boundaries and calculation controls are recorded before a release decision.
Only an approved, documented series may receive a public level or return display.
No rough-auction series is presented as polished pricing, and no D2C asking price is presented as a completed transaction.
Private source identities, record-level provenance and listing contribution remain outside the public page.
The Market Evidence Index is non-GNRC and does not create a GNRC valuation, RVB or NAV result.
The methodology page explains the source layers, held-research boundary and audit controls that govern this work.
