Rare Red Fluorescent Fluorite, Ojuela Mine, Mapimi, Mexico
A small percentage of purple fluorite from the Ojuela Mine in Mapimi, Durango, Mexico, shows a beautiful, rich, red fluorescence under UV. This is a very rare and unusual fluorescent response for fluorite, as blue, purple and white are the most common colors of fluorescence seen in this mineral. This is a spectacular example of red fluorescent fluorite from Mapimi, Mexico. Under visible light, soft purple cubes of gemmy fluorite are seen on a red/brown colored matrix. Under long wave UV the fluorite fluoresces a beautiful cherry red color, and under mid wave UV the fluorite shows a pink/red response. Interestingly, the fluorite also shows dimmer purple fluorescence under short wave UV. The size of this piece is 10.3 x 6.8 x 3.2 cm, and it weighs 150 grams.
Although the mechanism of red fluorescence is poorly understood in these fluorites from Mapimi, it is thought to be in part due to an interplay between trace amounts of the elements europium, oxygen and samarium substituting for calcium in the fluorite crystal structure.