CRYSTAL MORPHOLOGY OF RED BERYL CRYSTALS FOUND IN THE THOMAS RANGE, JUAB COUNTY, UTAH

In 2011 and 2012, the Geosciences Department of the University of West Georgia took an experiential learning trip to the Thomas Range, Juab County, Utah. Among the specimens collected on Topaz Mountain by the students were several small, tabular red beryl crystals ranging in size from 2mm to 7mm. In comparison to the red beryl studied by Shigely and Foord (2003) from the Violet Mine, Wah Wah Mountains, Utah, the crystals collected from Topaz Mountain differ significantly. The crystals found at Topaz Mountain are not of gem quality, lack dimension and clarity, and include an exceptional feature that occurs only at this location.

The red beryl crystals collected from Topaz Mountain were found in vugs of the topaz rhyolite with vapor phase topaz and Mn-Fe bearing hematite. These crystals are euhedral and show the basic beryl structure. Most of the samples that were discovered were detached and encrusted in quartz. These crystals are orangey-red to reddish-pink in color and exhibit slight color zonation. In hand sample, interpenetration twins of minute crystals are visible on two of the beryl terminations examined thus far. Other crystals exhibit the ‘stepped basal pinacoid termination’, also visible in hand sample. The c-axis of these crystals, however, is shortened compared to the width of the crystal: length: width is 1:4 compared to the red beryl found at the Violet Mines which are 4:1 (Shigley and Foord, 2003).

Analyses of the crystals found have included examination by hand sample and Scanning Electron Microscope (SEM). Future research includes further examinations of the crystals in hand sample and additional SEM data, including line scans and data point analyses to better determine trace elements and composition of the mineral. Studying this mineral’s formation, structure and mineralogy, may aid in finding other localities that present better quality red beryl crystals.