BULL. GEOL. SOC. AM. 



Vol. 19, 190?, PL. 13 









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FiGiRE 1. — Topaz Cuy.stals ix a lithophy.sal Cavity, Thoma.s Range, Utah 



5/4 natural size 



FiGiRE 2. — OrAQiE Toi'Az Crystal.s, Tho.ma.s Range, Utah 

 The upper left hand cluster are "rough," the others "smooth." 4/5 natural size 



TOPAZ CRYSTALS FROM UTAH 



