Smithsonite

Formerly known as Calamine, Smithsonite was renamed in 1832 in honor of James Smithson, the founder of the Smithsonian Institution. Its unusual luster, often described as the glow of melted wax under candle flame, sets it apart from other gemstones.

In addition to its unique luster, Smithsonite is also known for its great color variations. Smithsonite is essentially Zinc Carbonate; however, Zinc is often partially replaced by other minerals, causing the color of this gemstone to vary. Copper is the source for green to blue coloring. Cobalt is the source for pink to purple coloring, while Cadmium is the source for Smithsonite's yellow color.

Although the apple green to blue green colors are the most common, the lavender color is probably the most sought after hue. Other colors include yellow, white, tan, brown, blue, peach, red, and colorless.

A common crystal habit of Smithsonite is a fascinating form called "botryoidal". This form has the appearance of grapelike clusters, which result in radiating fibrous crystals that form from central attachment points and grow outward into each other. Other crystal habits also include rounded rhombohedrons and scalenohedrons.

Containing Zinc as the major element in its chemical composition, Smithsonite until the 1880s was considered to be the principal source of Zinc. Today, it is still being used, but to a lesser degree, as metamorphism and new altering processes are used to form new zinc ore minerals.

Smithsonite forms in dry climates as a weathering product of Sulfide Zinc ores such as Sphalerite. Some of the major sources of this gemstone include Tsumeb, Namibia and the Broken Hill Mine in Zambia. The Kelly Mine in Magdalena, New Mexico, and other locations in South America and Europe also produce some of the finest specimens.