Mercury: Characteristics
The only liquid metal, and why toxicity ended its reign
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 | about 210 t primary mine output (USGS 2025e); about 1,200 t on the World Mining Data basis (2024) | USGS shows China 200 t, Kyrgyzstan 5 t, Tajikistan 4 t. World Mining Data shows China 700 t, Tajikistan 300 t and Mexico 150 t in 2024. By-product and recycled mercury add an unquantified amount; the US made 103 t in 2021. | USGS MCS 2026; World Mining Data 2026; US EPA via USGS |
| Inventory and stock levels | large stranded stocks: 182 t held by US makers (2021); projected global excess about 13,100 t (2020) | US and EU export bans send surplus mercury to storage. The US DOE contracted a long-term store for up to 7,000 t in November 2024. One study projects cumulative excess mercury peaking near 17,400 t in 2028, many years of legal demand. | USGS MCS 2026; J. Material Cycles and Waste Management (2023) |
| Capacity utilisation | not published | No capacity data exist. Primary mines in China, Kyrgyzstan and Tajikistan run under Minamata Convention phase-out rules, and their output estimates differ by a factor of five between sources. | USGS MCS 2026; World Mining Data 2026 |
| Geographic and producer concentration | China about 94% of USGS-listed mine output, HHI about 8,900 (2025, derived); WMD 2024: China 58%, Tajikistan 25%, Mexico 12%, HHI 4,178 | Company data are not published. Chinese output mostly feeds the domestic vinyl chloride (PVC) industry. | USGS MCS 2026 (derived); World Mining Data 2026 |
| Supply elasticity | policy-bound: supply cannot expand legally | The Minamata Convention bars new primary mercury mines and phases out existing ones within 15 years of entry into force for each party. By-product supply from gold and zinc follows those metals. Illegal supply responds to artisanal gold prices. | Minamata Convention on Mercury, Article 3; USGS MCS 2026 |
| Project pipeline and CapEx | no new primary capacity; supply growth is from by-product capture and recycling | Closure of mercury-cell chlor-alkali plants and the switch from fluorescent lamps to LEDs release mercury for recycling or storage. Only one US mercury-cell chlor-alkali plant still operated in 2025. | USGS MCS 2026 |
| Logistics and export flows | world HS 280540 exports about $49 million (2023) | Tajikistan (45.9%) and the UAE (39.7%, a trading hub with no mines) led exports; South Africa (42.7%), India (19.9%) and Togo (14.6%) led imports in 2024. Mercury moves in 34.5 kg flasks. Much trade toward artisanal gold mining is informal, and exports need Minamata written consent. | UN Comtrade 2023-2024; Minamata Convention |
Material characteristics Metal / hard commodity
Mercury is the only metal liquid at room temperature. Its high density, uniform thermal expansion, electrical conductivity and ability to dissolve gold into an amalgam made it useful in switches, thermometers, lamps, dental fillings, chlor-alkali cells and gold recovery. Toxicity now limits almost all uses, so purity and legal status matter more than performance.
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Purity / grade | 99.99% commercial; 99.9999% (triple-distilled) for instruments and labs | Higher grades command a premium; trade is in 76-lb (34.5 kg) flasks | USGS MCS 2026; industry practice (indicative) |
| Melting and boiling point | -38.8 C; 356.7 C | Liquid over a wide range, which suited thermometers and switches; low boiling point lets retorts recover it | CRC Handbook of Chemistry and Physics |
| Density | 13.53 g/cm3 | Used in barometers, manometers and as a heavy liquid | CRC Handbook of Chemistry and Physics |
| Vapour pressure | about 0.27 Pa at 25 C | Evaporates readily, so spills and amalgam burning expose people to toxic vapour | CRC Handbook of Chemistry and Physics |
| Amalgamation | dissolves gold and silver at room temperature | The reason artisanal gold miners buy it, now the largest use | USGS MCS 2026 |
| Electrical conductivity | about 1.0 x 10^6 S/m as a liquid | Served as the flowing cathode in mercury-cell chlor-alkali plants and in relays | CRC Handbook of Chemistry and Physics |