black opal
Noun
Meaning
a dark colored opal with internal reflections of green or red
Source: WordNetSynonyms
Hypernyms
Examples
The black opal is said to be some of the best examples found in Australia.
The largest polished black opal in the Smithsonian Institution comes from the Royal Peacock opal mine in the Virgin Valley, weighing 160 carats, known as the "Black Peacock".