Mica King pegmatite, Yinnietharra, Upper Gascoyne Shire, Western Australia, Australiai

Regional Level Types
Mica King pegmatite	Pegmatite
Yinnietharra	Station (farming)
Upper Gascoyne Shire	Shire
Western Australia	State
Australia	Country

The Mica King pegmatite is also confusingly known as the Morrissey Hill pegmatite, but is different to the Morrissey Hill Mindat listing, which is 200 metres south of Mica King.

The Mica King pegmatite is just south of the east-west track, which in turn is north of Morrissey Hill itself. The pegmatite is 20 metres long and up to 10 metres wide. It is thought to be a quartz-microcline core, surrounded by a microcline-muscovite-quartz wall zone. Sheet muscovite forms a 2 metre thin concentration in the inner portions of the wall zone, and piles of it from the mining process can be found south-west of the pegmatite. Species include albite (variety cleavelandite), apatite, beryl, columbite, microcline, muscovite, and quartz.

The pegmatite was first observed by H.C. Stokes in 1918, and was visited by R.C. Wilson in 1922, both describing beryl either here or at the nearby Mica East pegmatite. We know mining was taking place in 1922, by a Mr Whitlock and Mr Spaven, who drilled and blasted a 32 metre long by 2.0-2.5 metre deep trench/opencut. Wilson viewed the mining methods employed as unprofessional, damaging and making the mica unusable. In 1926, the lease was held by the Australian Prospecting and Development Syndicate, and on-site manager, a Mr Coggan, deepened the open cut to 7.6 metres, and produced 3.25 tonnes of mica, before the syndicate filed for bankruptcy later the same year. Gaps exist in the literature due to the remote nature of the location. It was next reported being mined by a Mr Spargo in 1940, who sunk a shaft at the western end of the open cut. Blasting for mica was also occurring at a cross-cut 6 metres south of the open cut, and again the observer (Ellis 1941b) stated it was being mined like a quartz-gold reef, damaging the mica. No further reports of mining could be found after this date.

Other Regions, Features and Areas containing this locality

References