Mineral: Autunite and Fluorite (variety stink-fluss)
Locality: Marienschacht Mine, Wölsendorf, Schwarzach bei Nabburg, Wölsendorf West District, Upper Palatinate/Oberpfalz, Bavaria/Bayern, Germany
Dimensions: 76x54x35mm

Description: Aggregates of yellow autunite and dark veinlets of violet ‘stink-fluss’ fluorite in altered granitic rock from the Marienschacht Mine. The uranium mineral autunite displays strong yellow-green fluorescence on the surface of this specimen (demonstrated in this photo under LW UV light). [Regarding the fluorite and uranium mineralisation at the locality: "The main course mass is fluorite of light violet blue and green color, stinkspar is not found in the presence of gneiss (this is not to say that gneiss is always present in fluorspar of different colours). Note: Light purple or blue fluorspar is not known from the Kuppel Mine (or later from the Marienschacht Mine), it is purple fluorspar. Of the uranium minerals, autunite was only found whilst the western part of the gangue, which starts in granite, was being mined. This mineral was distributed over veins and cracks that ran through the reddish-coloured granite." ~ Drechsler, Dr. Franz, Hochschule München: "Zur Mineralführung und Chemie der Oberpfälzer Flußspatgänge". Die Befahrung des Reviers hat im Jahre 1923 stattgefunden; in "Sonderdruck aus dem 17. Bericht für das Jahr 1924 des Naturwissenschaflichen Vereins Regensburg E. V"., Seite 1 - 48, Regensburg 1925.]

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