Brendan M. Laurs, Thomas W. Overton
This article, from the Summer 2009 issue of Gems & Gemmology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemmology.
Read MoreKevin Lane Smith, December 1, 1988
Recent mining at Opal Butte in northeastern Oregon has produced a wide variety of large flawless opals.
Read MoreJames E. Shigley, Brendan M. Laurs, and Nathan D. Renfro
Commercial quantities of gem-quality chrysoprase and green prase opal (nickel-bearing chalcedony and common opal, respectively) have been recovered from altered serpentinite deposits near Haneti, Tanzania.
Read More