This gray opal shows a wide range of hues in its play of color. "Precious opal (Bulldog Shale, Lower Cretaceous; Coober Pedy Opal Field, South Australia) 1," photo by James St. John. Licensed under CC By 2.0.
Article: Eight Opal Types Explained
Credit: James St. John
|Natural or man made||Natural|
|Origin details||Coober Pedy Opal Field, South Australia|
|Photo phenomena||Play of Color|