Opal occurs as nodules in volcanic rocks at a new gem opal locality in the Menz Gishe district of Shewa Province, Ethiopia.

After almost 75 years of inactivity, the deposits of boulder opal in Queensland, Australia, began to attract new interest in the 1960s and 1970s.

Recent mining at Opal Butte in northeastern Oregon has produced a wide variety of large flawless opals.

An examination of the challenges of carving gem-quality opal.