"Nickel" is a color that resembles the metal nickel. Copper plated with nickel and gold is often used. Mines produce gold, silver, zinc, cobalt and nickel. These are molybdenum, vanadium, niobium, tantalum, zirconium, manganese, iron, chromium, cobalt, nickel, and copper. Metal salts used included the sulfates and/or chlorides of copper, cobalt, iron, nickel, and manganese. Tattoo inks may contain heavy metals, such as chromium, cobalt, nickel, and copper. The Upper Peninsula is rich in mineral deposits, including iron, copper, nickel and silver. These alloying ingredients include chromium, molybdenum, silicon, manganese, nickel and vanadium. Examples include iron, nickel, lead and zinc. Magnum and were available in blued, nickel, silver, and gold plated finishes. Stainless steel welding is suspected of producing carcinogenic fumes from cadmium oxides, nickel, and chromium. Green stains also result from foods with chlorophyll or excessive exposure to copper or nickel. High temperatures require expensive alloys made from nickel or cobalt, rather than inexpensive steel. The nation is also a notable producer of copper, nickel and coal. The islands are rich in undeveloped mineral resources such as lead, zinc, nickel, and gold.