This is a large cluster of transparent, modified rhombohedral calcite crystals on limestone matrix. It was collected in 2016 from the Linwood Mine, Scott County, Buffalo, Iowa. At its best under mid wave UV, this piece shows a moderate pink/purple response. Under short wave UV the calcite fluoresces a dimmer red/pink color. A dim red-orange response is seen under long wave UV. This specimen measures 7.5 x 7.0 x 4.0 inches.
Located adjacent to the Mississippi River, the Linwood Mine is one of the largest underground limestone mines currently in operation in the United States.
As shown above, a soft pink/purple response is seen under mid wave UV (302 nm).
Red/pink fluorescence is seen under short wave UV (254 nm).
Under long wave UV (365 nm), dim red/orange fluorescence is seen.
Same calcite specimen shown under visible light.