# Rubidium: Characteristics

Cesium's near-twin, and what sets its price

Source page: https://www.materialinsights.org/commodities/rubidium/characteristics/

Cesium's near-twin, and what sets its price What this tab covers The supply and physical characteristics of the commodity. Supply: current production, inventories and stocks, capacity utilisation, geographic and producer concentration, how fast supply responds to price, the project pipeline and capital spending, and logistics and export flows. Material: the physical and chemical properties that set its grade, price and end uses (for example purity and conductivity for metals, API gravity, sulfur and energy content for fuels, moisture, protein and fibre quality for crops).

#### Supply volume characteristics

| Characteristic | Figure | What it means | Source |
|---|---|---|---|
| **Current production volume** | no reported mine production in 2025; refined compounds from stockpiles | All known rubidium ore mining has stopped: Namibia in the early 2000s, Bikita's pollucite in 2018, Sinclair in 2019. Refiners in China and Germany processed stockpiled ore. US use is under 2,000 kg a year. | USGS MCS 2026, Rubidium |
| **Inventory and stock levels** | commercial ore stockpiles; tonnage not published, may be depleted 'in the near future' | USGS reports that at current processing rates, world commercial stockpiles of rubidium ore may be depleted soon without new mining. There is no exchange or government stockpile. | USGS MCS 2026, Rubidium |
| **Capacity utilisation** | not published | With no mine output, mine utilisation is effectively zero. Refining capacity in China and Germany runs on stockpiles; no rate is disclosed. | USGS MCS 2026 |
| **Geographic and producer concentration** | refining in China and Germany (and Russia); HHI not computable | No production data exist. Sinomine (China) is the main known refiner of cesium and rubidium salts. Reserves in Australia, Canada, China and Namibia total under 200,000 t of recoverable rubidium materials. | USGS MCS 2026; Sinomine disclosures |
| **Supply elasticity** | very low: pure by-product of cesium and lithium processing | Rubidium is not a major constituent of any mineral, so supply rises only if pollucite or lepidolite is processed with a rubidium circuit. Higher rubidium prices alone do not trigger mining. | USGS MCS 2026 |
| **Project pipeline and CapEx** | pilot and feasibility only | Mount Edon (Western Australia): 3.6 Mt inferred resource with about 7,900 t Rb2O, 97% recovery in initial tests, pilot scale-up planned for 2026. Karibib (Namibia): 23,000 t Rb measured and indicated, in administration from end-2024. No CapEx published. | USGS MCS 2026 |
| **Logistics and export flows** | not tracked separately in trade data; gram to kilogram lots | Rubidium falls under 'alkali metals, other' and generic salt HS codes. Metal ships sealed in ampoules under inert gas because it ignites in air. | USGS MCS 2026 (tariff codes) |

#### Material characteristics Metal / hard commodity

Rubidium is a soft, highly reactive alkali metal very similar to cesium, slightly less electropositive. Its commercial value comes from specialty glass (fibre optics), atomic frequency standards, photoemissive devices and research such as quantum computing with ultracold atoms. Purity and form (metal or salt) set price; ore grade sets whether recovery is ever economic.

| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| **Purity / grade** | Metal at 99.75% (metal basis); salts and formate at 99.8% | Price basis: 1 g at 99.75% $138, 100 g $2,453 (2025) | USGS MCS 2026 |
| **Ore grade** | Lepidolite up to 3.5% Rb2O; pollucite up to 1.5% Rb2O | Low grades make standalone mining uneconomic | USGS MCS 2026 |
| **Melting point and density** | about 39 °C; about 1.53 g/cm3 (indicative, handbook values) | Liquid on a warm day; must be sealed under argon | CRC Handbook (indicative) |
| **Atomic frequency standard** | Rb-87 hyperfine transition about 6.8 GHz | Basis of compact rubidium oscillators for telecoms and GPS timing | USGS MCS 2026 (use); frequency indicative from standard references |
| **Natural radioactivity** | Rb-87 (about 28% of natural rubidium) is weakly radioactive, half-life about 49 billion years (indicative) | Very low activity; no known health issues from natural rubidium (USGS) | USGS MCS 2026; nuclear data tables (indicative) |

## Other sections

- [Summary](https://www.materialinsights.org/commodities/rubidium/index.md)
- [Overview](https://www.materialinsights.org/commodities/rubidium/overview/index.md)
- [Correlation](https://www.materialinsights.org/commodities/rubidium/correlation/index.md)
- [Extraction](https://www.materialinsights.org/commodities/rubidium/extraction/index.md)
- [Production](https://www.materialinsights.org/commodities/rubidium/production/index.md)
- [Stocks](https://www.materialinsights.org/commodities/rubidium/stocks/index.md)
- [Cycles](https://www.materialinsights.org/commodities/rubidium/cycles/index.md)
- [Trading](https://www.materialinsights.org/commodities/rubidium/trading/index.md)
- [Movement](https://www.materialinsights.org/commodities/rubidium/movement/index.md)
- [Criticality](https://www.materialinsights.org/commodities/rubidium/criticality/index.md)
- [Emissions](https://www.materialinsights.org/commodities/rubidium/emissions/index.md)
- [Relationships](https://www.materialinsights.org/commodities/rubidium/links/index.md)