5 1/2 LB Smithsonite Specimen

This specimen weighs 5 1/2 pounds, has a pleasant color, and a lovely botryoidal mass to it. The specimen was mined from the El Refugio Mine, Choix, Choix Municipality, Sinaloa, Mexico.

Smithsonite is a secondary zinc mineral (a zinc carbonate: ZnCO3). It typically forms as the principal zinc mineral, sphalerite, deteriorates or oxidized. It has a wide color range and in this case the color is due to trace amounts of copper and iron replacing some of the zinc in the crystalline structure.