The White Cliffs area in far western New South Wales is the oldest opal producing site in the state. The opal produced here is not the exotic black opal found at Lightning Ridge, but is a quality gem which has proven popular throughout the world since the commencement of mining here in 1889.
White Cliffs opal has formed in a similar manner to Lightning Ridge gems, and is hosted by rocks of similar Cretaceous age and type. The more arid setting of White Cliffs, and the presence of mesa-like landforms has created a uniquely interesting area for the geotourist. Significantly, the elevated topography associated with the original discoveries at White Cliffs and the environment characterised by extremes of temperature has led to the unique use of abandoned mine workings as dwellings, known locally as dugouts.
The downloadable geological guide presents a brief history of the White Cliffs opal field, and outlines the local geology, forms and modes of occurrence of opal, and describes the theory of opal formation. One easily accessible geological site is described where the opal host rocks can be observed and their significance explained.
