Feature Gems & Gemology, Winter 1984, Vol. 20, No. 4

Gem-Quality Red Beryl from the Wah Wah Mountains, Utah

James E. Shigley and Eugene E. Foord

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A detailed investigation of the gem-quality red beryl from the southern Wah Wah Mountains, Utah, has confirmed the unique mineralogical and gemological character of this material. At the Violet Claims, red beryl is found associated with minor bixbyite in a volcanic rhyolite host rock. Analytical data gathered on the red beryl indicate relatively high contents of the minor or trace elements Mn, Ti, Zn, Sn, Li, Nb, Sc, Zr, Ga, Cs, Rb, B, and Pb, which are generally low or absent in other gem beryls. Measured refractive indices (1.564-1.574), specific gravity (2.66 -2.70), and unit-cell parameters (a= 9.222 Aº, c= 9.186 Aº) of the red beryl are distinct from most other beryls. The red beryl is thought to have crystallized along fractures, in cavities, or within the host rhyolite from a high-temperature gas or vapor phase released during the latter stages of cooling and crystallization of the rhyolite magma.