Natrolite and microcline from Mont Saint-Hilaire, Quebec, Canada
Shown here is a really nice cluster of translucent natrolite crystals, associated with misshaped microcline crystals. As usual, the natrolite crystals show a bright green uranyl-activated response under shortwave UV; the natrolite also fluoresces under midwave but SW is the brightest. The microcline fluoresces the typical dull red response of feldspar. Nice specimen, both under UV and in visible light. Non fluorescent light brown siderite is also present. Cabinet sized specimen; it measures 12,8 cm X 9,4 cm X 8 cm.
The specimen is shown here fluorescing under shortwave UV. As it's usually the case, only the tip of the natrolite crystals fluoresces, which is actually a good thing, since the green fluorescence is so bright that the dull red response of the microcline would be overwhelmed by the fluorescence of the natrolite if the entire crystals fluoresced.
Specimen shown in white light; while not being among the most spectacular MSH natrolites, this specimen is pretty nice both under UV and white light, unlike so many of our glow rocks!