White Cliffs fire opal deposits, White Cliffs Station, Laverton Shire, Western Australia, Australiai

Regional Level Types
White Cliffs fire opal deposits	Group of Deposits
White Cliffs Station	- not defined -
Laverton Shire	Shire
Western Australia	State
Australia	Country

Government geologist E.S. Simpson in his work Minerals of Western Australia from the first half of the Twentieth Century mentioned this location. He describes it as flame opal, rich red-brown in colour and a high translucency. 'A 4 carat piece was brilliant and flawless when cut about 1926, but after 3 years storage in a drawer, it had developed many cracks, possibly as a result of dehydration'.

This is not uncommon for the species. It has not stopped other prospectors in recent decades from cutting gems from the deposits, although the limited reports found indicate the results were no better than in 1926. The material is probably best as specimens, but no-one has seen it profitable enough to market it as such.

The White Cliffs are 35 kilometres north-east of Laverton along the White Cliffs Road. (This location is not the same as the precious opal deposits at White Cliffs NSW).

Opal in the area is found as planar fracture and joint fillings, containing clear yellow, orange and red opal, capable of up to 30 carat stones. Alternatively the material is found as rounded reworked fault filling, where the opal exhibits a fractured multiphase growth habit.

The source states the opal is likely have formed from sub-tropical weathering and laterization during post Triassic times.

The opal is hosted in laterite overlying granite. The seams run approximately 50 metres vertically, judging by exposures, however the majority of it is clear jelly opal, with coloured material restricted to the ferruginous laterite caprock. None of it exhibits opalescence.

The planar type opal is more economically important, while the later type is harder to work and returns non gem grade potch of various colours, clarity and attractiveness.

The source is a prospector who formed a syndicate in recent years to mine the material. Either they did not read Simpson or decided to plough on regardless. He states they produced 1200 carat of stone of far better quality, clarity and colour than the more well known Mexican material. He also states he lost vast sums of money on the enterprise, as the stone has 5 to 6 % moisture and cracks readily, 50% of the cracks appearing within the first 3 months of the stone being cut.

The Mindat co-ordinates are approximate.

Other Regions, Features and Areas containing this locality

References