Surat Al-Hadid is the 57th Surah of the Qur'an prefixed by the Basmala (the 9th. sura is not - see also Sunnan Abu Dawood ahadith 785-787). This sura is the only one named for a chemical element.
The word iron (Hadid) occurs 6 times in the Qur'an. The 6th occurrence of the word iron, and the only one in this sura, is in the 26th. ayah (counting the Basmala (q.v.)).
The above-mentioned verse states: "...anzalna (We sent down) al-hadid (Iron), wherein is mighty power and many benefits for mankind...".
The only other chemical elements mentioned in the Qur'an are gold and silver as valuables (e.g. Sura 3, 14 & Sura 9, 34), and copper in the context of molten brass or bronze (e.g. Sura 34, 12). None of these are anywhere described as "sent down".