Group 12 element zinc and cadmium which makes geological separation unlikely. As a consequence, cadmium is produced mainly as a byproduct from mining, smelting, and refining sulfidic ores of zinc, and, to a lesser degree, lead and copper. One place where metallic cadmium can be found is the Vilyuy River basin in Siberia. Although mercury is an extremely rare element in the Earth's crust, because it does not blend geochemically with those elements that constitute the majority of the crustal mass, mercury ores can be highly concentrated considering the element's abundance in ordinary rock. The richest mercury ores contain up to 2.5% mercury
Group 5 element magnesium. 230,000 metric tons of niobium ore are produced yearly, with Brazil producing metric 210,000 tons, Canada producing 10000 metric tons, and Australia producing 1000 metric tons. 60000 metric tons of pure niobium are produced each year. 70000 metric tons of tantalum ore are produced yearly. Brazil produces 90% of tantalum ore, with Canada, Australia, China, and Rwanda also producing the element. The demand for tantalum is around 1200 metric tons per year. Dubnium is produced synthetically by bombarding actinides with lighter elements. Vanadium's main application is in alloys, such as vanadium steel. Vanadium alloys are used in springs, tools,