This was a fortuitous find at a local mineral show. Just like with oysters, one never knows what one will find in a geode. In addition to the green fluorescing quartz [likely uranyl activated] it has calcite [fluoresces pink red] and aragonite [fluoresces faint blue]. The calcite fluorescence is caused by phantoms within while the aragonite also phosphoresces. Shortwave ultraviolet fluorescence on left, natural light on right. SW pictures taken at ISO-100, f/11 and 2.5 seconds. No pictures of the phosphorescence as it was pale and brief. No real LW fluorescence. 1 pound 8 ounces. 6 x 4 1/2 x 1 1/2 inches.
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