Iron is one of the four most abundant elements in the world and it has been one of the most vital metals for mankind.

The Quranic verse referring to Iron is as follows in Surat Al-Hadid

Quran 57:25 -
"...And we sent down iron in which there lies great force and which has many uses for mankind."

This verse incorporates two very interesting mathematical codes.

"Al-Hadid" (Iron) is the 57th surah of the Quran. The numerical value (in the Abjad system of Arabic in which each letter has a numerical value) of the letters of the word "Al-Hadid" is the same: 57.

The numerical value (Abjad) of the word "Hadid" (iron) alone, without the definite article "al", is 26 and 26 is the atomic number of iron.

Ref: For Men of Understanding (2nd ed.) By Harun Yahya