Welo opal (also spelled Wollo opal) is a type of precious opal mined in Ethiopia’s Wollo Province, near the town of Wegel Tena. Although small occurrences were noted in the early 1990s, large-scale deposits were discovered in 2008, propelling Ethiopian opal onto the global gemstone market. Unlike earlier Ethiopian opals from Shewa Province, which were darker and less stable, Welo opals are generally more transparent to translucent, often hydrophane (able to absorb water), and considered mor...
