Fluorapatite, fluorescing One of the more eerie seeming properties of some minerals is their ability

Fluorapatite, fluorescingOne of the more eerie seeming properties of some minerals is their ability to glow in the dark when submerged in ultraviolet light, fluorite (after which the phenomenon was named when discovered) being the most obvious example. Atoms within the crystal lattice get excited by the high energy rays, and their electrons jump up with this extra energy to a different shell. They can’t hold on to it though, and shed it as they drop back in the form of light at visible wavelengths.The 5.5 x 4.1 x 1.8 cm example in the photo is a colour zoned fluorine rich apatite (see http://bit.ly/2akYWkg for a detailed discusion) from the Panasqueira Mines of Portugal. As the crystal grew, a pulse of the fluid from which it precipitated was charged with a colour causing impurity which created the green zoning. As you can see, the electrons in this zone of the crystal absorb and shed the energy differently, with higher energy blue wavelengths coming off the white portion of the crystal, and a lovely yellowish green from the coloured portion.LozImage credit: Rob Lavinsky/iRocks.com -- source link

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