Category Nuances for rare_earth:

• inorganic,
• obnoxious,
• organic,
• catalytic,
• heavy,
• metallic,
• insoluble,
• new,
• valuable,
• specialized,
• novel,
• commercial,
• exotic,
• reactive,
• large,
• vital,
• nuclear,
• difficult,
• heavier,

Simple Categories for rare_earth:

• medium,
• mineral,
• component,
• material,
• commodity,
• substance,
• constituent,
• atom,
• impurity,