(Reuters)

China announced sweeping export restrictions on Tuesday targeting five metals used across defence, clean energy and other industries minutes after an additional 10% tariff on Chinese goods imposed by U.S. President Donald Trump came into effect.

Here is what you need to know about these metals:

TUNGSTEN

Tungsten is an ultra-hard metal – in terms of strength outdone only by diamonds – and is primarily used in the production of goods including artillery shells, armour plating and cutting tools.

Approximately 60% of its U.S. consumption goes to making tungsten carbide, a highly durable material widely used across construction, metalworking, and oil and gas drilling.

Like many other critical minerals, China dominates the production and export of tungsten and produced just over 80% of global supply in 2023.

Based on analysis by UK-based consultancy Project Blue, China supplies 30% of the ex-China market, mostly in the form of powders for tooling applications.

Other producers include Vietnam, Russia, South Korea, and Spain.

Tungsten has not been mined commercially in the United States since 2015, according to the U.S. Geological Survey (USGS).

INDIUM

Indium is a vital part of phone screens and TV displays via a refined product called indium tin oxide. A separate indium product is also used in fibre-optic technology.

The expansion of fifth-generation (5G) cellular networks has led to greater demand for indium.

As with tungsten, China is the leading producer, accounting for 70% of the global total, according to the USGS. As of September 2024, a quarter of U.S. indium imports came from China.

Other major buyers from China include Japan and South Korea, according to Project Blue.

BISMUTH

Bismuth is used in solders, alloys, metallurgical additives, medications and atomic research.

The U.S. ceased production of primary refined bismuth in 1997 and is highly import reliant, according to USGS.

China produced over 80% of the world’s roughly 13,000 tons of bismuth last year, data from USGS also showed.

South Korea and Laos are other major producers.

TELLURIUM

Tellurium, usually a byproduct of copper refining, is used across metallurgy, solar panels, memory chips and other products.

China produced about three quarters of the world’s refined tellurium in 2024, according to USGS.

While the U.S. has two refineries which produce the precursor, copper telluride, it is then shipped overseas for further processing, according to the USGS. Most products using tellurium relied on imports of the metal.

MOLYBDENUM

Molybdenum is primarily used to strengthen and harden steel alloys, making them more resistant to heat and corrosion. It is also used in lubricants, pigments, and as a catalyst in the petroleum industry.

China accounted for about 40% of global production, versus 12% for the U.S. in 2024, according to USGS.

(Reporting by Ashitha Shivaprasad in Bengaluru and Amy Lv and Lewis Jackson in Beijing and additional reporting by Sherin Elizabeth Varghese and Anjana Anil; Editing by Kate Mayberry)