Opals are some of the most unique gemstones on Earth. They range from milky white to fiery red and deep blue-green, and all have a kaleidoscope of shimmering colors within, called play-of-color. Here ...

At almost 10,000 feet above sea level, villagers in northern Ethiopia have uncovered a seam of pure black opal buried within hand-dug tunnels. The site, hidden in Wollo Province’s rugged terrain, is ...