This is a lovely fluorescent specimen featuring numerous zircon crystals and minor fluorite in a non-fluorescent quartz matrix. Collected from the Eureka Tunnel, St. Peters Dome, El Paso Co., Colorado. The size of this piece is 54 x 45 x 25 mm.
Located in the Pikes Peak area of Colorado, St. Peter's Dome has been the site of numerous fluorspar and other mining operations dating back to the early 1900s. St. Peter's Dome is a a granite-topped peak on the Pikes Peak massif in the Pike National Forest.
The above photograph shows the specimen under mid wave UV (302 nm). This wavelength provides the best overall fluorescent response inducing bright golden yellow fluorescence from the zircon crystals and blue from the fluorite.
The zircon crystals show their brightest response under short wave UV (254 nm), above, but the fluorite only fluoresces a dim, pale blue.
As seen above, the zircons fluoresce a moderate orange color under long wave UV (365 nm), while the fluorite shows its brightest blue response.
The above photograph shows the same specimen under visible light. Numerous red/purple colored zircon crystals in a grey/white translucent quartz matrix with minor blue/grey fluorite. There is also an unidentified greenish mineral present, possibly epidote.