Vanadium (V) is a transition metal with a silvery-gray appearance. It is found in various minerals, notably vanadinite and carnotite, and is used primarily in the production of steel alloys such as high-speed tool steels. Its compounds are known for their vibrant colors and are used as catalysts, dye and print mordants, and in the manufacture of certain kinds of glass. Vanadium steel is known for its high strength and resistance to wear, making it useful in automotive parts, tools, and springs. Vanadium redox flow batteries, which take advantage of the multiple oxidation states of vanadium, are also being developed as a method for large-scale energy storage. The metal's natural occurrence in living organisms is still a topic of study, though it has been recognized in certain marine organisms and fungi.