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Sydney dust storm analysed by Museum mineralogist

By: Rebecca Hancock, Category: Science, Date: 23 Sep 2009

Australian Museum mineralogist Ross Pogson took no time at all to analyse the mineral content of the dust that swept across Sydney this morning, enveloping the city in an eerie red blanket.

Dust storm Sydney 23 September 2009

Mark Connolly © Mark Connolly, Australian Museum

Minerals don’t always come in large and attractive crystals, but can be as fine as dust. Sydney’s record-beating dust storm gave Australian Museum Mineralogist Ross Pogson an opportunity to study these ‘dusty minerals’. He carefully brushed some dust off the bonnets of cars in the Museum’s car park early this morning and analysed the sample with an X-ray Diffractometer, adjusting the machine to give the best results for these very fine-grained particles.

The high and low peaks which slowly revealed themselves on the computer screen showed familiar patterns to a trained eye. Preliminary results show the major mineral in the dust is Quartz (silica), together with minor amounts of the clay mineral Kaolinite (aluminium silicate-hydroxide) and a very fine-grained mica (potassium, aluminium silicate-hydroxide). The red-brown colour is from goethite (iron oxide-hydroxide), which is so intensely coloured that only a small amount is needed to give the dust a good colour. Unfortunately the mineral contents do not allow exact origins of the dust to be determined, but it is believed to come from the general central Australia region.

Story by Ross Pogson

Tags dust storm, Sydney, mineral analysis,

4 comments

erikajoy - 2.09 PM, 25 September 2009
Hey Sydney...the Nullabor called...they want their top soil back. (and their freaky dust animals) Kthnxbai
Lynda Kelly - 3.09 PM, 24 September 2009
Have a look at Ross's graph that has been uploaded on the top right hand side of the page - it is a pdf file
Lynda Kelly - 6.09 AM, 24 September 2009
And another!

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Lynda Kelly - 6.09 AM, 24 September 2009
Hey Ross - here's some images that went round on the web from the dust storm :-)

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