Titanium – This naturally occurring metal has the highest tensile strength to density ratio of any metal, which makes it, pound-for-pound, stronger than tungsten. It scores lower on the Mohs scale of hardness, though. Titanium alloys are strong and lightweight and are often used in the aerospace industry.
Titanium is the ninth most abundant element on Earth. It is almost always present in igneous rocks and the sediments derived from them. It occurs in the minerals ilmenite, rutile and sphene and is present in titanates and many iron ores.