כְּרוֹם, with the chemical symbol Cr and the atomic number 24, belongs to group VIB in the periodic table. The element name comes from the Greek word meaning “color”, because chromium compounds have color. It is the hardest metal in nature. Chromium is the 17th most abundant metal in the earth’s crust at 0.01%. Natural chromium in its free state is extremely rare and is mainly found in chromium-lead ores.