Highlights

• Certificates of Analysis (COAs) are the commercial truth stamp in rare earth trade, where fractional percentage differences in composition or impurity levels can swing millions of dollars in pricing, payment release, and contract settlement.
• Credibility begins with ISO/IEC 17025 accreditation—major TIC firms like SGS, Intertek, Bureau Veritas, and ALS Global, plus specialist umpire labs like Ledoux & Company, provide the independent verification buyers demand in cross-border transactions.
• COAs are only as strong as their calibration, sampling methodology, and chain-of-custody—geopolitical trust gaps and analytical method discipline (ICP-MS, ICP-AES, XRF) now define whether rare earth market participants wire funds or walk away.

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A Certificate of Analysis (COA) is not clerical paperwork. It is the commercial “truth stamp” that defines what is actually inside a rare earth concentrate, oxide, metal, or magnet alloy. In rare earth trade, pricing, acceptance, payment release, letters of credit, and arbitration can hinge on fractional percentage differences in neodymium, dysprosium, or impurity thresholds such as thorium and uranium. A 0.2% variance in TREO or a missed impurity limit can swing millions of dollars.

Rare Earth Exchanges™ has previously outlined the foundational structure: COAs are issued either by in-house producer laboratories or independent third-party testing firms. In cross-border trade—especially ex-China transactions—buyers frequently require independent verification, and contracts often designate an “umpire” laboratory whose results are binding in case of analytical dispute.

Accreditation Is the Real Barrier to Entry

Credibility in this market does not begin with marketing claims—it begins with accreditation.

The dominant global benchmark for laboratory competence is ISO/IEC 17025, which certifies technical proficiency in testing and calibration. Accredited labs operate within a defined scope of approved analytical methods.

International acceptance is supported through the mutual recognition framework of the International Laboratory Accreditation Cooperation (opens in a new tab) (ILAC). ILAC’s system allows accredited results to be recognized across borders, provided the testing falls within the lab’s approved scope.

Sophisticated buyers, therefore, ask:

• Is the method (e.g., ICP-MS, ICP-AES, XRF)* within the accredited scope?
• Who is the authorized signatory?
• Is the chain-of-custody documented?
• Are retained samples available for dispute resolution?

In rare earths, method discipline matters as much as the instrument.

* ICP-MS (Inductively Coupled Plasma–Mass Spectrometry), ICP-AES/OES (Inductively Coupled Plasma–Atomic/Optical Emission Spectroscopy), and XRF (X-Ray Fluorescence) are the main laboratory methods used to measure rare earth composition on Certificates of Analysis (COAs). ICP-MS dissolves a sample and injects it into a super-hot plasma, then uses a mass spectrometer to detect and count ions by weight, making it extremely sensitive for trace elements and impurities like thorium and uranium. ICP-AES works similarly with plasma but measures the light emitted by excited atoms rather than their mass, making it reliable for higher concentration, percent-level analysis in concentrates. XRF, by contrast, analyzes solid samples directly by bombarding them with X-rays and measuring the characteristic fluorescent signals of each element; it is fast and non-destructive but less sensitive for very low concentrations. In the rare earth trade, ICP-MS is often used for high-purity products and dispute resolution, ICP-AES for routine composition analysis, and XRF for rapid screening, because the chosen method can materially affect reported grades, pricing, and contract settlement.

The TIC Giants: Referees of Global Trade

The global testing, inspection, and certification (TIC) sector anchors rare earth COA issuance.

• SGS (opens in a new tab) operates geochemistry laboratories worldwide and provides rare earth analytical packages using ICP-MS, ICP-AES, and XRF methods. SGS is frequently referenced in mining disclosures and port-based trade inspection.
• Intertek (opens in a new tab) provides independent minerals inspection, sampling, and trade assurance services. In rare earth transactions, sampling methodology is often more consequential than instrument precision.
• Bureau Veritas (opens in a new tab) supports the metals and minerals trade globally, operating accredited laboratories across major mining and shipping hubs.
• ALS Global (opens in a new tab) is a major geochemistry provider in exploration and critical mineral workflows. ALS-generated assays often underpin resource estimates, feasibility studies, and financing disclosures.

These firms operate on scale, geographic coverage, and accreditation depth. They serve miners, traders, smelters, refiners, and financial institutions alike.

Specialist “Umpire” Laboratories

When contracts escalate into disputes, smaller specialist laboratories often become decisive.

• Ledoux & Company (opens in a new tab) holds ISO/IEC 17025 accreditation and has long served as a referee laboratory in settlement-grade assays.
• Activation Laboratories (opens in a new tab) (Actlabs) operates globally accredited geochemistry services and is frequently cited in public mining disclosures.
• Conti Testing Laboratories (opens in a new tab) provides ISO/IEC 17025:2017-accredited analytical services, including rare earth ICP-MS testing.

These firms, and others, compete on technical specialization, dispute credibility, and method transparency.

China: In-House Dominance, Third-Party Infrastructure

In China’s domestic rare earth trade, large producers frequently rely on internal laboratories operating under GB/T national standards. However, third-party verification also exists.

• China Certification & Inspection Group (opens in a new tab) (CCIC) provides third-party inspection and verification services for metals and minerals.
• China National Accreditation Service for Conformity Assessment (opens in a new tab) (CNAS) is an ILAC Mutual Recognition Arrangement signatory for ISO/IEC 17025 testing. CNAS accreditation is central to international acceptance of Chinese laboratory results.

Multinational TIC firms—including Bureau Veritas and SGS—also operate within China under CNAS and China Metrology Accreditation (CMA) frameworks.

The geopolitical reality: trust in COAs increasingly intersects with jurisdiction.

The Calibration Backbone: Reference Materials

COAs are only as strong as their calibration.

• National Institute of Standards and Technology (opens in a new tab) (NIST) issues Standard Reference Materials (SRMs) with certified values.
• OREAS (opens in a new tab) produces ISO 17034-accredited certified reference materials widely used in mining and geochemistry.
• Bundesanstalt für Materialforschung und -prüfung (opens in a new tab) (BAM) also produces ISO 17034-certified reference materials.

These reference material producers underpin analytical comparability across labs worldwide.

The Real Risks: Where COAs Fail

• Sampling bias
• Poor chain-of-custody
• Out-of-scope methods
• Reagent variability
• Geopolitical trust gaps

Fraud in COAs is rare among accredited labs—but analytical drift, sampling variance, and documentation failure remain real commercial risks.

The Bottom Line

In the rare earth trade, the COA is currency.

The laboratories are the mint.

And in a supply chain increasingly defined by geopolitics, processing bottlenecks, and purity constraints, the market is learning to inspect the watermark before wiring funds. Accuracy is not assumed. It is accredited.