Translation guide
In English, "rare earth" refers to a group of chemically similar metallic elements (the rare earth elements) or their oxides. In Japanese, the term is usually translated directly, but there are important distinctions between the elements themselves and their compounds.
Referring to the set of 17 metallic elements including the lanthanides plus scandium and yttrium.
The most common term, borrowed from English. Used in news, industry, and everyday conversation.
レアアースはハイテク製品に不可欠です。
Rare earths are essential for high-tech products.
The native Japanese term, often used in scientific or technical contexts. Literally 'rare earth group'.
希土類元素は周期表でランタノイドに属します。
Rare earth elements belong to the lanthanides in the periodic table.
Explicitly 'rare earth elements'. Used in chemistry and materials science.
希土類元素は化学的性質が似ています。
Rare earth elements have similar chemical properties.
Referring to the naturally occurring compounds or the oxides extracted from them.
Short for 'rare earth', often used in compound words like 希土鉱物 (rare earth mineral) or 希土酸化物 (rare earth oxide).
この鉱山では希土が採掘されています。
Rare earths are mined at this mine.
Specifically 'rare earth oxide'. Used when the oxide form is important, such as in refining or magnet production.
レアアース酸化物は磁石の原料です。
Rare earth oxides are raw materials for magnets.
レアアース is the everyday loanword, while 希土類 is the native technical term. In news media, レアアース dominates. In scientific papers, 希土類 is more common. Both refer to the same group of elements.
レアアースの輸入が増えている。
Imports of rare earths are increasing.
希土類の分離技術が進歩した。
Separation technology for rare earths has advanced.
Do not translate 'rare earth' literally as 珍しい土 (めずらしいつち). That means 'unusual soil' and is incorrect. The term refers to specific metallic elements, not dirt.
中国はレアアースの最大の生産国です。
China is the largest producer of rare earths.
レアアース磁石は電気自動車に使われています。
Rare earth magnets are used in electric vehicles.