The El Refugio Mine, located in Choix, in the Mexican state of Sinaloa, is a notable source of beautiful specimens of the zinc carbonate mineral smithsonite. These specimens are often very colorful and display well under normal light. Some of this material also shows a deep, intense fluorescent response under short wave UV, usually in colors of blue and/or pink. This example consists of botryoidal white to blue/green smithsonite that shows a soft blue fluorescent response under short wave UV. The size of this specimen is 40 x 29 x 26 mm.
This specimen shows a soft blue fluorescent response under short wave UV (254 nm). It is not fluorescent under long wave UV (365 nm).
Same specimen shown under visible light. This piece features white to blue/green, botryoidal masses of smithsonite on a red/brown matrix on limonitic gossan.