Zinc white is made from zinc oxide. Common engineering metals include aluminium, chromium, copper, iron, magnesium, nickel, titanium, zinc, and silicon. Excessive absorption of zinc suppresses copper and iron absorption. Varying amounts of potassium, sodium, phosphorus, calcium, magnesium, iron, and zinc were present. These include such metals as zinc, magnesium, and cadmium. Brass is an alloy of copper and zinc. Carbon, copper, gold, iron, lead, mercury, silver, sulfur, tin, and zinc. Brass is an alloy made from copper and zinc. Also, selenium interacts with other minerals, such as zinc and copper. Arsenic is mainly encountered occupationally in the smelting of zinc and copper ores. Mines produce gold, silver, zinc, cobalt and nickel. Depletion of zinc and accumulation of manganese may play a role. Alloys of copper with either zinc or silver are the most common. ISO 4520 specifies chromate conversion coatings on electroplated zinc and cadmium coatings. Examples include iron, nickel, lead and zinc.