And why is it so expensive? Black opal is one of the most enchanting stones in the world, sought after for its seemingly infinite display of colors. Compared to common opal, which is usually one ...

FELTON — An amateur miner hopes to sell what he believes is one of the largest common fire opals in America uncovered near his farm in Idaho. Jim Hartrim, a local gem jeweler, was tending his ...

Most of the opal is "common opal," which isn't worth much. But geologists found some of the highly valued "precious opal," leading them to conclude that there was more to be found. Fremont County ...