The composition, provenance, and appearance of Ethiopian and Australian opals differ greatly, despite the fact that both are valued for their striking color display. Australian opals, valued for their stability and bright, intense colors, are found mostly in Coober Pedy and Lightning Ridge. The Welo region is home to Ethiopian opal gemstones, which are hydrophane, meaning they absorb water and can temporarily change their color and transparency. 

In addition to a greater variety of colors, Ethiopian opals often include bright orange and red flashes. Australian opals are valued for their constancy, whereas Ethiopian opals are valued for their dynamic changes and affordability. Collectors value both because of their unique characteristics, each of which has a certain allure.