BEIJING (Reuters) - U.S. President Donald Trump’s proposed tariffs on another $200 billion of Chinese goods threaten a niche trade in minor metals and rare earths used in everything from stomach remedies and jet engines to consumer electronics.

A bulldozer and a labor work on a pile of iron ore at a steel factory in Tangshan in China's Hebei Province November 3, 2015. REUTERS/Kim Kyung-Hoon/File Photo

More than 6,000 items have been earmarked for a 10 percent import tariff, including - in some form - 32 of the 35 minerals the United States in May designated as “critical” to its economic and national security.

These minerals and products based on them accounted for well over $1 billion of U.S. imports from China in 2017, and traders warn U.S. consumers will end up paying a premium if tariffs are put in place, albeit one cushioned by the recent devaluation of the yuan.

Below is a list of mineral products in the tariff list where the United States relies heavily on China.

(GRAPHIC: U.S.-China minor metals and minerals - tmsnrt.rs/2LwZWbE)

* Bismuth

No primary refined production of bismuth has taken place in the United States since 1997. Applications for this white metal with a pinkish hue range from stomach remedies to sprinkler systems, and China accounted for 77 percent of U.S. bismuth imports over 2013-2016, according to the United States Geological Survey (USGS). This includes waste and scrap and totaled $22.8 million last year.

* Barite

Used as a weighting agent in oil and gas drilling, barite is another mineral the United States mainly sources from China, which accounts for 69 percent of its imports. The value of these stood at $93.6 million last year, when U.S. domestic barite mine production fell.

* Antimony

A shiny semi-metal used in fire retardants, antimony, together with its powder form antimony oxide, accounted for $108.5 million of imports from China last year. China provided 62 percent of antimony metal and 70 percent of antimony oxide imports from 2013-16, according to the USGS.

* Natural graphite

Long used in steelmaking and more recently as anode material for lithium-ion batteries, natural graphite was not produced in the United States last year. China is the top supplier, accounting for 35 percent of imports over 2013-16, with a value of around $27 million in 2017, although Mexico and Canada are alternative sources.

* Tungsten

Used to harden steel, Chinese tungsten items had an import value of around $145 million last year. China, the world’s top producer of the metal, accounts for 34 percent of U.S. imports.

* Titanium

An element used in aerospace, titanium and titanium oxides had an import value of $84.9 million in 2017, while there was an additional $89.1 million of titanium dioxide pigment imports. China is a distant second to Japan with an 8 percent share of titanium sponge metal imports, but accounted for 24 percent of imports of titanium dioxide, used as a pigment in paints.

* Tantalum

Used in capacitors for consumer electronics and in super-alloy castings for jet engines, imports of tantalum items were worth $72.7 million last year. China accounts for 23 percent of the various import sources but a trader reported suppliers have been “really rushing” to ship in tantalum from China so it can clear customs before possible tariffs in late August.

* Cobalt

Most mined cobalt supply comes from the Democratic Republic of Congo, but China is a leading supplier of refined cobalt to the United States, according to the USGS. Various forms of cobalt last year accounted for $65.3 million tonnes of imports into the United States, where the main use is in super-alloys in aircraft gas turbine engines. China provides 15 percent of U.S. supply, just behind Norway.

* Rare earths

This group of 17 elements is used in magnets, consumer electronics, radars and lasers. The USGS puts the value of U.S. rare-earth compounds and metal imports last year at $150 million, with China making up 78 percent of imports over 2013-16. Separately, permanent magnets and articles intended to become permanent magnets - which could include rare earth oxides neodymium and praseodymium - accounted for $191 million of imports from China in 2017.

* Iron oxides and hydroxides

Iron oxide is mainly used as a pigment in construction materials. China provided 52 percent of the United States’ synthetic iron oxide pigments (IOPs), according to the USGS, which also notes, however, that “domestic and world resources for production of IOPs are adequate.” This category accounted for $94.6 million of imports.