@zsphoenix: 水銀 is mercury (to remember better, think water silver -> quicksilver -> mercury). Magnesium doesn't have an associated kanji　（鎂　is Chinese hanzi, not Japanese kanji), and is written in katakana form, as マグネシウム.

Also, magnesium sulfide is not found in nature, except in extraterrestial meteorites.

NNescio said:

@zsphoenix: 水銀 is mercury (to remember better, think water silver -> quicksilver -> mercury). Magnesium doesn't have an associated kanji　（鎂　is Chinese hanzi, not Japanese kanji), and is written in katakana form, as マグネシウム.

Also, magnesium sulfide is not found in nature, except in extraterrestial meteorites.

Yeah, that was my mistake. I glossed over the English when I edited it because it looked similar to what I was intending...