Caesium: Cycles
A metal priced only by the catalogue ampoule
What this tab covers Price history and what drives booms and busts, including this commodity's super-cycles, the drivers behind them and the metrics to track. It charts monthly prices (World Bank) with a switch to inflation-adjusted annual prices; where there is no World Bank series it uses USGS US prices.Cesium metal is not traded in commercial quantities, so there is no market price. Catalogue prices are the only signal. A 1-gram ampoule of 99.8% cesium cost $104 in 2025, up 6% from $98 in 2024. Salts rose 7% to 8%. Such small, steady rises say more about scarcity of suppliers than about demand swings. The real risk is discontinuous. When a pegmatite like Bikita or Tanco runs out of pollucite, supply depends on stockpiles until a new by-product source starts.
US price, 1-gram ampoule, 99.8% cesium (metal basis), one supplier
2024 98.0 2025 104 dollars per ampoule. USGS MCS 2026; 2025 is an estimate.Super-cycles in caesium
Cesium has no exchange price and no market cycle in the usual sense. It is a tiny, concentrated market where one mine, Tanco, long set supply. The main events are supply exhaustion, not demand booms: Bikita's pollucite ran out in 2018 and Sinclair in 2019, leaving Sinomine as the dominant supplier. Catalogue prices for small lots rise steadily, by 6-8% a year in 2024-2025. Revenue for Sinomine's cesium and rubidium segment rose by half in H1 2025, which suggests tight supply and firm pricing for formate and salts.
- 2018-2019
Bikita (Zimbabwe) ran out of pollucite ore reserves in 2018 and Sinclair (Australia) completed mining of economic pollucite in 2019, cutting the number of active sources to essentially one.
no market price published (USGS)
- 2024-2025
Supply came from Tanco's intermittent output, stockpiles and Bikita tailings. Catalogue prices rose across products.
1-g ampoule of 99.8% cesium $98 (2024) to $104 (2025); 50 g of cesium carbonate $146.40 (2025), up 7-8%; 25 g cesium formate $52.40 to $56.10 (USGS MCS 2026)
- H1 2025
Sinomine's cesium and rubidium segment grew sharply on formate and salt sales.
Segment revenue RMB 708 million in H1 2025, up 50.43% year on year (Asian Metal, Aug 2025)
What drives the cycle
- Pollucite supply from a few mines. Exhaustion or restarts at Tanco, Bikita and Sinclair decide availability.
- Lithium prices. Future cesium will come mostly from lepidolite and spodumene projects that need lithium margins to proceed.
- Deep high-pressure drilling. Formate brine demand depends on HPHT well activity, mainly offshore.
- Chinese processing control. Sinomine owns the main mines and plants, and Bikita tailings go to China.
Metrics to track
| Metric | Why it matters | Where to track it |
|---|---|---|
| Sinomine rare light metals segment revenue and margin | Best public proxy for the market | Sinomine interim and annual reports (Shenzhen Stock Exchange) |
| Tanco operating status | Main primary source | Sinomine announcements; USGS MCS |
| Catalogue prices for cesium metal and salts | Only public price series | USGS MCS (from supplier catalogues) |
| Lithium price and lepidolite project financing | Sets new by-product supply | Benchmark Mineral Intelligence; company releases |