Tantalum capacitors are manufactured from a powder of relatively pure elemental tantalum metal. The characteristics of niobium electrolytic capacitors and tantalum electrolytic capacitors are roughly comparable. Niobium capacitors are available as alternative to tantalum capacitors, but tantalum capacitors still predominate. Hafnium is used in alloys with iron, titanium, niobium, tantalum, and other metals. The ore contains such rare metals as beryllium, lithium, tantalum, and niobium. CVD for molybdenum, tantalum, titanium, nickel is widely used. Natural rutile may contain up to 10% iron and significant amounts of niobium and tantalum. In many ways, niobium is similar to tantalum and zirconium. Copper can be directly electroplated onto ruthenium, in contrast to tantalum nitride. Separation of the tantalum and niobium is then achieved by pH adjustment. Lower voltage applied may have positive influences for tantalum electrolytic capacitors. This confusion arose from the minimal observed differences between tantalum and niobium. The Solid Capacitor Business Group produces tantalum and ceramic capacitors. There were also tungsten, tantalum and uranium mines in the vicinity. Investigation indicates that addition of rhenium and tantalum increases oxidation resistance.