Smithsonite, or zinc spar (zinc carbonate) is a mineral ore of zinc. Smithsonite was identified with hemimorphite before it became clear that they were two distinct minerals. The term Calamine has been used for both, since these two minerals are very similar in appearance

The mineral smithsonite was named in 1832 after James Smithson who first identified the mineral in 1802.

Smithsonite is a variably colored mineral rarely is found in well formed crystals. It is brittle and can have a pearly or silky luster. It is translucent or opaque. It can exist in blue, yellow, green, yellow green, orange yellow, pink, purple, grey, brown colors or be colorless.

It has a hardness of 4.5 in Moh’s scale of mineral hardness. Smithsonite occurs as a secondary mineral in the zinc-bearing ore deposits.