It is typically found in rock and sand deposits, from which it is mined and refined. It is a lustrous, gray-white, strong transition metal that closely resembles hafnium and, to a lesser extent, titanium. It is malleable and ductile and easily forms stable compounds. It is also highly resistant to corrosion. Because of its high tolerance to corrosion and its strength, zirconium is present in several compounds in various medical uses.