3.85" Sky-Blue, Botryoidal Hemimorphite - Qaleh-Zari Mine, Iran

This is a beautiful, vibrant sky-blue, botryoidal formation of hemimorphite. This specimen was collected from the Qaleh-Zari Mine in the South Khorasan Province of Iran. This location has been actively mined since the early 1970's, but until the 2000's mineral specimens were kept from the public eye making anything that comes out of the mine relatively rare.

Hemimorphite is a basic hydrous zinc silicate with the chemical composition Zn4Si2O7(OH)2 · H2O. It earned its name from the Greek terms that best define its crystal structure. It has two different terminations on each side of the crystal, hence the inclusion of the greek terms "hemi", meaning half, and "morph", meaning shape. The crystal formations can range anywhere between a crystal druze or botryoidal formation to radiating acicular crystals and more. Hemimorphite has been found in shades of white, beige, light brown, and a bright, electric blue. It can also form as yellow and green crystals on rare occasions.

Prior to 1803, hemimorphite and smithsonite were thought to be the same mineral, called "calamine". However, further scientific research concluded that these were two distinct minerals.
Qaleh-Zari Mine, Nehbandan County, South Khorasan Province, Iran
3.85 x 2.8"