Beyond the headlines
Rare earths have become a geopolitical headline. For a glass processor, a lens laboratory or an optics manufacturer buying cerium oxide polishing compounds, the headlines are mostly about other elements. The questions that actually matter are more practical:
- Availability — can I be supplied, at the volumes I need, without interruption?
- Price — what will it cost next quarter, and why does it move?
- Proof and compliance — can I show what I bought, and can I import it legally into my country?
This article answers these three questions with public data, then sets out what a well-managed supply chain for polishing compounds should look like — and how we run ours.
1. Where cerium comes from — and why it is not scarce
Rare-earth supply is highly concentrated. According to the US Geological Survey, China mined about 270,000 of the 390,000 tonnes of rare-earth oxide produced worldwide in 2025, around 69 % [1]. Concentration is even higher downstream: the International Energy Agency estimates that China accounts for about 91 % of global rare-earth separation and refining [2]. Whatever the brand on the bag, the cerium oxide in a polishing powder has very probably passed through Chinese refining.
But concentration does not mean scarcity. Rare earths occur together in the same ores, and cerium is the most abundant of them. Researchers at KU Leuven call this the “balance problem”: ore deposits deliver rare earths in natural proportions that do not match market demand. Lanthanum and especially cerium are “very abundant and cheap”, and cerium is produced in excess of demand [3].
WHAT THIS MEANS FOR A POLISHING BUYER
The availability risk on cerium is structurally low: it is a surplus co-product. The real risks lie elsewhere: in price, because cerium output follows decisions driven by demand for other elements, notably magnet metals; in lot-to-lot consistency; and in documentation.
2. Export controls: separating fact from noise
China has tightened its export controls on rare earths in several steps. Here is what they cover, as of 30 September 2026:
| Measure | Scope | Cerium / lanthanum? |
| April 2025 controls — in force | Samarium, gadolinium, terbium, dysprosium, lutetium, scandium and yttrium, including their oxides, compounds, metals and alloys [1] | Not covered |
| October 2025 measures — suspended until 10 November 2026 | Holmium, erbium, thulium, europium, ytterbium, plus related technologies, equipment and foreign products containing Chinese rare earths [4]. No extension had been announced as of early September 2026 [5] | Not covered |
| State Council Order No. 834 — in force since 31 March 2026 | General framework on industrial and supply-chain security, allowing countermeasures against foreign entities judged to harm Chinese supply chains [6] | Not specific to rare earths |
Two further signals deserve attention because they reduce visibility rather than supply. In 2024, China published mining and separation quotas of 270,000 and 254,000 tonnes. In 2025, quotas were issued without the usual public statement, and only two state-owned groups received them [7]. Buyers now have less public information to anticipate supply decisions.
Our reading: cerium and lanthanum are not controlled, and a supplier who suggests otherwise to justify a price or an urgency is misinforming you. The compliance climate around Chinese supply chains is tightening, however, and it increases the documentation burden on anyone who imports directly.
3. Price volatility: the real operational risk
Abundant does not mean stable. The USGS reports an average price for cerium oxide (99.5 % minimum) of US$1.21/kg in 2024 and US$1.71/kg in 2025 — a 41 % increase in one year [1]. History shows larger swings: mischmetal, a cerium–lanthanum-rich alloy, traded at US$8–9/kg in 2009, US$45–55/kg in 2010 and US$17–18/kg in 2012 according to the USGS [8].
Two caveats help read these numbers correctly. First, the price of a raw oxide is not the price of a polishing powder: grading, calcination, particle-size engineering, quality control, packaging and documentation all add value, and that is where products differ. Second, because cerium is a co-product, its supply responds to decisions made for other elements — quotas, magnet demand, policy — not only to demand from glass polishing.
A buyer cannot remove this volatility. A good supplier can make it visible and predictable: a dated market reference with every quote, a revision rule agreed in advance, and early warning when the market moves.
4. Consistency: the supply risk that shows up on your line
For most workshops, the most expensive supply-chain failure is not a missed delivery; it is a lot that behaves differently. Research at Lawrence Livermore National Laboratory has shown that scratches and roughness are driven by the coarse tail of the particle size distribution and by a small number of oversized particles or agglomerates, not by the median size [9][10]. A lot whose tail shifts can create defects even if its nominal specification is unchanged.
This is why traceability matters. A certificate of analysis should accompany every lot, reporting at minimum the particle size distribution including the coarse tail, the rare-earth oxide composition and the lot number, and it should be traceable back to the producer’s own production lot. When your process drifts, you can then connect the drift to a specific lot instead of guessing.
5. Compliance: the documents that decide whether a shipment clears
The customs code for cerium compounds is HS 2846.10. Beyond classification, each destination has its own documentary requirements. The main ones for our markets:
| Market | Key requirements | Reference |
| United States | The importer or its agent must certify to US Customs (CBP) that the chemical substances in the shipment comply with TSCA (positive certification). The safety data sheet must meet OSHA’s Hazard Communication Standard. Duties on Chinese-origin products have changed several times since 2018: check the current rate for HTS 2846.10 at the time of order. | EPA; 40 CFR 707.20; 19 CFR 12.118–12.127 [11]; 29 CFR 1910.1200 |
| Canada | Under WHMIS, the supplier must provide the safety data sheet in both English and French, delivered directly to the purchaser (a download link alone is not acceptable). | CCOHS / Hazardous Products Regulations [12] |
| Brazil | Safety data sheets must follow ABNT NBR 14725:2023, which replaced the former FISPQ with the FDS format; the transition period ended in July 2025. | ABNT NBR 14725:2023 [13] |
| Gulf states | Conformity and customs documentation requirements vary by country and are best handled with a local importer of record. | Confirm per country |
Two practical consequences. First, the importer of record carries the legal obligations: a supplier can prepare and provide the information, but it cannot sign the TSCA certification on a US importer’s behalf. Second, in several markets a qualified local distributor is not an optional convenience; it is often the most reliable way to import compliantly.
6. What supply chain mastery looks like
| Risk | What to demand from any supplier | Why |
| Price volatility | Dated market reference with each quote; written revision rule; notice period | Turns an unpredictable cost into a managed one |
| Lot variation | Certificate of analysis per lot, including the coarse tail of the PSD; traceability to the producer’s lot | Scratches come from the tail [9][10] |
| Compliance | MSDS in the required format and language for your country; information needed by your importer of record | Legal obligation; avoids customs delays [11][12][13] |
| Single-source dependency | Disclosure of the producing source, so you can check it differs from your current supplier’s | A second source that shares the same producer is not a second source |
| Misinformation | Claims about export controls backed by a primary source | Cerium and lanthanum are not controlled [1][4] |
How Illumine Consultants manages its supply chain
- Sourcing: we work with a vetted panel of high-volume Chinese producers, selected through a long-standing local partner and qualified against the technical criteria a Western reference producer would apply.
- Traceability: every lot ships with a certificate of analysis, traceable to the producer’s lot.
- Price transparency: every quote carries a dated market reference, and our revision rules are stated before you order.
- Documentation: technical data sheet, safety data sheet, and the information your importer of record needs.
- Logistics: shipments leave directly from the producer, without intermediate stock.
- Honesty about second sourcing: if your current supplier draws on the same producer as us, we will tell you — because in that case we would not be a genuine second source.
Key takeaways
- Rare-earth supply is concentrated in China (≈ 69 % of mining, ≈ 91 % of refining), but cerium and lanthanum are abundant co-products [1][2][3].
- Cerium and lanthanum are not covered by China’s 2025 export controls; the October 2025 measures, suspended until 10 November 2026, do not cover them either [1][4].
- Price volatility is the real operational risk: cerium oxide rose 41 % between 2024 and 2025 [1].
- Lot-to-lot consistency is a supply chain issue; ask for a certificate of analysis per lot, including the coarse particle tail [9][10].
- The importer of record carries the compliance obligations; the right supplier makes them easy to meet [11][12][13].
About the author. Olivier M. spent eight years in rare-earth polishing solutions at Solvay before founding Illumine Consultants, an independent supplier of cerium- and lanthanum-based polishing compounds (CERITOP and LUCERIS ranges).
This article relies exclusively on public sources, listed below, and reflects the regulatory situation as of 30 September 2026. It is general information, not legal or customs advice: import requirements should be confirmed for each shipment with your customs broker or counsel.
References
[1] U.S. Geological Survey, Mineral Commodity Summaries 2026 — Rare Earths. pubs.usgs.gov/periodicals/mcs2026/mcs2026-rare-earths.pdf (accessed 30 Sept 2026).
[2] International Energy Agency, “With new export controls on critical minerals, supply concentration risks become reality”, commentary, 23 October 2025. iea.org.
[3] K. Binnemans, P. T. Jones, “Rare Earths and the Balance Problem”, Journal of Sustainable Metallurgy 1, 29–38 (2015). doi:10.1007/s40831-014-0005-1.
[4] CIRS Group, “China Temporarily Suspends Export Controls on Key Raw Materials, Including Rare Earths, Lithium Batteries, and Diamonds”, November 2025. cirs-group.com (accessed 30 Sept 2026).
[5] East Asia Brief, “China export pause on rare earths nears Nov. 10 expiration”, 6 September 2026. eastasiabrief.com (accessed 30 Sept 2026).
[6] White & Case LLP, “China issues new supply chain security regulations” (State Council Order No. 834, 31 March 2026). whitecase.com (accessed 30 Sept 2026).
[7] Reuters, “China quietly issues 2025 rare earth quotas, sources say”, July 2025, as republished by MINING.COM. mining.com (accessed 30 Sept 2026).
[8] U.S. Geological Survey, Mineral Commodity Summaries 2013 — Rare Earths (mischmetal price series 2008–2012).
[9] T. Suratwala et al., “Effect of rogue particles on the sub-surface damage of fused silica during grinding/polishing”, Journal of Non-Crystalline Solids 354(18), 2023–2037 (2008). doi:10.1016/j.jnoncrysol.2007.11.015.
[10] T. Suratwala et al., “Microscopic Removal Function and the Relationship Between Slurry Particle Size Distribution and Workpiece Roughness During Pad Polishing”, Journal of the American Ceramic Society (2014). doi:10.1111/jace.12631.
[11] U.S. Environmental Protection Agency, “TSCA Requirements for Importing Chemicals”. epa.gov/tsca-import-export-requirements (accessed 30 Sept 2026).
[12] Canadian Centre for Occupational Health and Safety (CCOHS), “WHMIS — Safety Data Sheet (SDS)”. ccohs.ca (accessed 30 Sept 2026).
[13] Lisam, “FISPQs x FDSs: o que muda com a entrada em vigor da ABNT NBR 14725:2023”. lisam.com (accessed 30 Sept 2026).