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 pink. This is such a specimen. It consists of botryoidal pink smithsonite on a larger mass of grey pitted smithsonite. Under short wave UV it shows a moderately bright, but intense saturated pink and blue fluorescent response. The size of this specimen is 56 x 37 x 32 mm, and it weighs 115 grams.

Smithsonite from the El Refugio mine in Sinaloa, Mexico, seen under short wave UV (254nm).

Same specimen, seen under visible light.