Zinc has a bluish color when in its natural state. As an alloy, zinc may be colorless or a number of other colors including red and green.
The discovery of zinc traces to the Romans during the time of Augustus, between 20 B.C. and 14 A.D., which is the earliest dating of brass. Zinc ore is used to make brass and other compounds. However, zinc was recognized as a unique metal in 12th-century India. European discovery of zinc as a separate metal occurred in the 16th century, when zinc smelting processes were developed.
Zinc is found naturally in the environment as minerals and metals but also appears in larger concentrations. Natural zinc is bluish-white or blue-gray in color. As an alloy, particularly where it is mixed with other metals, zinc takes on additional colors. For example, bayldonite is an alloy of zinc, copper and lead and has a green color. Adamite, a zinc arsenate, is also green. Legrandite is another zinc arsenate with the same formation as adamite but with added water for hydration; it is bright orange.
As a reactant, zinc forms different colors as well. For example, blue copper chloride solution turns reddish when a zinc strip is added. Also, zinc produces green crystals when it is in silicate form.