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Roger Weller, geology instructor                     

Fluorescent Minerals
Steve Tyminski
Physical Geology
Fall 2007

          Willemite is a zinc silicate and a minor ore of zinc. It is highly fluorescent (green) under shortwave ultraviolet light. It occurs in all different colors in daylight. Willemite is usually formed as an alteration of previously existing sphalerite ore bodies, and is usually associated with limestone. It occurs in many places, but is best known from Arizona and the world famous zinc, iron, manganese deposits at Franklin Furnace, New Jersey. Willemite was discovered in 1830 and named after William I of the Netherlands.


          This example of Willemite / Calcite / Hydrozincite is from the State of Texas Mine in the Huachuca Mountains of Cochise County, AZ.  Specimens are from the private collection of Roy Parsons.


Willemite, Calcite, Hydrozincite, normal light
Willemite is white / Calcite dark gray, Hydrozincite dark



 Willemite, Calcite, Hydrozincite, under ultraviolet light
Willemite is green / Calcite is red, Hydrozincite is blue

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